Free U.S. Shipping & Lifetime Warranty For All Endura Flap Pet Doors

  • Installs in sliding doors without permanent construction
  • Magnetic-sealed flap supports a more consistent barrier against drafts
  • Flexible flap remains functional in extreme temperature conditions
  • Insulated glass panel adds structure and improved thermal performance
  • Compression fit holds securely without drilling into the frame
  • Includes locking cover and track-mounted lock for controlled access

Endura Flap Thermo Panel 3e

Insulated Access for Sliding Doors

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Made in the USA USA flag icon
Regular price $579.99 USD

Fast & Free Shipping in the USA.

Satisfaction Guarantee -

Lifetime Warranty

Color: White
Flap Size
Height Adjustment Range


A premium sliding glass insert with a magnetic-sealed Endura Flap, insulated glass panel, and secure compression fit designed to deliver everyday pet access without permanent modification.

Installation & Fit

  • Designed specifically for aluminum sliding patio doors with track width at least 1 inch
  • Compatible with standard recessed tracks and monorail track configurations
  • Monorail installations use a dedicated adapter to integrate the panel more cleanly
  • Fits within standard sliding door track height ranges with a built in 3 inch adjustment span
  • Available in short, regular, tall, and custom panel heights to match a wide range of patio doors
  • Installs as a removable panel without cutting into your existing door or wall

Best Suited For

Ideal for:

  • Aluminum sliding patio doors with track width at least 1 inch
  • Monorail track setups using the monorail adapter
  • Homes that want pet access without cutting into doors or walls
  • Windy or colder conditions where a magnetic sealing flap helps reduce drafts
  • Buyers who want the option to lock the pet opening when needed
  • Larger pets that benefit from taller flap options

Not ideal for:

  • Sliding doors with track width under 1 inch
  • Andersen or Pella sliding doors without modification
  • Vinyl patio door tracks (We recommend the Endura Flap Vinyl insert or Severe Weather Vinyl insert instead
  • Customers needing a dual pane glass option - we offer a Dual Pane Thermo Panel 3e
  • Very small cats or small dog breeds

Questions

What's in the box?

  • Panel Pet Door
  • Foam Weather Strip
  • Center Post Weather Seal Draft Stopper
  • Sliding Door C-Clamp Lock
  • Flathead Screwdriver

Can an intruder remove a dog door for sliding glass doors from the outside?

No, the adjustment locks are on the inside of the panel, so once installed, the Endura Flap Panel cannot be lifted out and removed without first loosening the adjustment locks from inside the home.

Can I install it myself?

It is meant to easily be put in and removed. You just have to loosen the screws at the top, fit it into the track, and then tighten them. Then to remove it you simply loosen them again and pop it out.

Can you lock the pet door?

It comes with a closing cover, and you slide that in on the inside of the house. It is a very secure ABS plastic material that is as strong as a 16 gauge steel.

Explore all questions
Product Details

Product Details

The Thermo Panel 3e is built for pet owners who want a more refined solution than a basic insert, without committing to permanent construction. It installs as a vertical panel within your sliding door track, allowing your existing door to remain intact while creating a dedicated entry point for your pet.

Built Around Real-World Compatibility
This model is designed for aluminum patio doors with a track width of at least 1 inch. It can also work with monorail track systems when paired with the appropriate adapter. Certain door systems, including Andersen and Pella sliders, may require additional consideration before installation, making them better approached as custom-fit scenarios.

At the center of the panel is the Endura Flap, constructed from a flexible polyolefin polymer that maintains usability in extreme cold and heat. Magnets along three sides help the flap return to position after each use, supporting a more controlled seal that resists wind pressure and helps limit unwanted airflow.

A More Substantial Panel Design
The glass section uses 3/16 inch clear safety glass, adding both rigidity and a more finished feel compared to thinner inserts. Combined with the aluminum frame, the panel is designed to hold its structure over time while maintaining a clean, integrated appearance within the door track.

Security and Control, Built In
For added peace of mind, the panel includes an interior locking cover that secures the pet opening when not in use. A track-mounted clamp lock also anchors to the sliding door frame, creating a defined stop point that helps prevent the door from being opened from the outside.

Sizing & Fit

Size Chart

Flap Dimensions:

6"w x 11"h

The entry way your dog goes through.

Overall Panel Width

10 3/16"

How wide your panel is.
flap dimensions
epanel width
step over height

Step-Over Height

3" - 4-1/2"

The distance from the bottom of the panel to the bottom of your flap.

Flap Dimensions:

8"w x 15"h

The entry way your dog goes through.

Overall Panel Width

12 1/4"

How wide your panel is.
flap dimensions
epanel width
step over height

Step-Over Height

3" - 4-1/2"

The distance from the bottom of the panel to the bottom of your flap.

Flap Dimensions:

10"w x 19"h

The entry way your dog goes through.

Overall Panel Width

14 1/4"

How wide your panel is.
flap dimensions
epanel width
step over height

Step-Over Height

3" - 6"

The distance from the bottom of the panel to the bottom of your flap.

Flap Dimensions:

12"w x 23"h

The entry way your dog goes through.

Overall Panel Width

16-3/8"

How wide your panel is.
flap dimensions
epanel width
step over height

Step-Over Height

3" - 6"

The distance from the bottom of the panel to the bottom of your flap.

Flap Dimensions:

14" w x 27" h

The entry way your dog goes through.

Overall Panel Width

18-3/8"

How wide your panel is.
flap dimensions
epanel width
step over height

Step-Over Height

3" - 7.5"

The distance from the bottom of the panel to the bottom of your flap.
Flap SizeFlap DimensionStep Over RangeOverall Panel WidthRecommended Pet Height
Small6" w x 11" h3" - 4-1/2" (ships at 3")10-3/16"9" - 15"
Medium8" w x 15" h3" - 4-1/2" (ships at 3")12-1/4"9" - 21"
Large10" w x 19" h3" - 6" (ships at 4-1/2")14-1/4"9" - 27"
Extra Large12" w x 23" h3" - 6" (ships at 4-1/2")16-3/8"9" - 34"
XX Large 14" w x 27" h 3" - 7.5" (ships at 6") 18-3/8" 9" - 41"

Note: Endura Flap is not recommended for kittens or very small dogs.

 

Important Information about Custom Heights

Custom Height Minimum & Maximum Heights
ModelMinimumMaximum
Small 35"100"
Medium 42"107"
Large 48"117"
Extra Large 46"123"


Custom orders are final sale once built. They are essential in two situations:

While most sliding glass door track heights are in the three standard height ranges offered, some are not. In those cases, we can build a Thermo Panel 3e in a custom height to fit your specific dimension. 

The second situation is when you have a side-sliding window. A sliding window is essentially a miniature sliding glass door, and you can install a custom height panel, provided the window track is at least 1" wide.

Installation Guide

Installation Information

One-Piece Panel

Installation icon Printable Version
Installation icon Difficulty Easy
Installation icon Steps 10
Installation icon Time Required 0.5 hours

Parts

  • Panel Pet Door
  • Foam Weather Strip
  • Center Post Weather Seal Draft Stopper
  • Sliding Door C-Clamp Lock
  • Flathead Screwdriver

Tools

  • Flathead Screwdriver

Please read instructions & notes thoroughly before installation.

Step 1 Loosen Height Adjustment Locks

Loosen Height Adjustment Locks
  • Loosen the height adjustment locks at the top of the pet panel with the screwdriver. This allows the spring mechanism to move freely up and down.

Step 2 Test Fit the Panel in Your Track

Test Fit the Panel in Your Track
  • You want to put the pet door in your track before applying any weather stripping to ensure it fits. If the panel fits well, proceed to the next step. See the Troubleshooting Section if you encounter difficulties.
  • To insert the panel into the top track, push up against the spring mechanism and swing the bottom of the panel up and over the threshold.
  • Seat the panel on top of the small guide rail in the track.
  • If you can't quite get it in the track, try swinging in from the outside as the outside track wall may be shorter.

Step 3 Adjust Step-Over Height (Optional)

  • The Endura aluminum sliding door panel has a patented Adjustable Step-Over feature which allows you to adjust the height of the flap to the most comfortable fit for your pet.
  • Adjusting the step-over requires tools that are not supplied. You will need a Phillips-head screwdriver, and we recommend using a power tool if available, as the screws were tightly installed to hold the panel together during shipping.
  • The top of the flap should be positioned to be at least 1” above the top of the pet's shoulder.
  • If the factory setting is not suitable, please adjust it before proceeding. Otherwise, proceed to the Installation Instructions section.

Step 4 Remove the Screws (Optional)

Remove the Screws (Optional)
  • Lay the entire panel on a flat surface.
  • Using the Phillips-header screwdriver, or selected power tool, remove the bottom side-screws and loosen the upper side screws.

Step 5 Adjust the Spacers (Optional)

Adjust the Spacers (Optional)
  • Once the bottom screws have been removed and the upper side-screws loosened, the Pet Door Assembly and spacers can be removed by sliding the sections down and out of the panel.

Step 6 Reconnect the Pieces (Optional)

Reconnect the Pieces (Optional)
  • Replace the spacers and the Pet Door Assembly by sliding them back in a different order to achieve the desired height. You can move the spacer below and above the flap to raise or lower the flap height.
  • It is critical that the bottom piece is placed at the base. This is the designated attachment point for the screws.
  • Make sure that the locking cover side of the flap frame is on the same side as the height adjustment locks.

Step 7 Retighten the Screws (Optional)

Retighten the Screws (Optional)
  • When finished, replace the bottom side-screws and tighten the next upper-side screws.
  • A lower step-over height is easier for pets to navigate. However, if the top of the flap is low enough that the pet needs to crouch to get through their pet door, they can injure themselves and possibly cause the pet door to malfunction. If your pet door does not sit at a comfortable height for your pet, you may need a larger flap size.

Step 8 Apply Weatherstripping

Apply Weatherstripping
Apply Weatherstripping
Apply Weatherstripping
  • Once you're sure the panel fits, remove it from the frame and lay it on its side on the ground.
  • For foam weatherstripping: Peel the backing off the foam weatherstripping. Press it along both edges of the panel, trimming as needed with scissors to ensure a snug fit.
  • For rubber weatherstripping: Clean the edge of your sliding door or window with rubbing alcohol to help the weatherstripping stick properly. Starting at the top or bottom, peel and press the strip into place with the folded edge facing indoors—align angled cuts if you have two pieces. For best results, apply the seal to the sliding door or window, but it can go on the pet door panel if needed.
  • Foam weatherstripping is applied onto both sides of the panel, but the rubber weather stripping only applies on the side of the slider door. Your panel will come with one type of weather stripping. You do not need both types.

Step 9 Install the Draft Stopper

Install the Draft Stopper
Install the Draft Stopper
Install the Draft Stopper
  • The center post weather seal strip (draft stopper) should be installed on the inside of the home.
  • It can install on either the back edge of the sliding door panel or the leading edge of the stationary panel.
  • This strip prevents air from leaking between the sliding glass door and the stationary panel.
  • Trim with scissors as needed. Clean the edge of your patio door with rubbing alcohol before installing to assure a good seal.
  • Repeat step two to install the panel in your track.

Step 10 Install the Panel

Install the Panel
  • If you haven't already, insert the panel back into your sliding door track the same way you did earlier: pushing up against the spring mechanism and swinging the bottom into place. Push it snug into the side track!
  • Make sure everything is sitting securely.
  • Tighten the height adustment locks in the spring mechanism.
  • And that's it! Your pet door is installed and ready for use. Now, watch your pet strut through their new door like they own the place!

Two-Piece Panel

Installation icon Printable Version
Installation icon Difficulty Easy
Installation icon Steps 11
Installation icon Time Required 0.5 hours

Parts

  • Top Glass Panel Section
  • Bottom Flap Section
  • Foam Weather Strip
  • Center Post Weather Seal Draft Stopper
  • 4 Flathead Screws
  • 1 Flathead Screwdriver
  • 1 Sliding Door C-Clamp Lock

Tools

  • Flathead Screwdriver

Please read instructions & notes thoroughly before installation.

Step 1 Adjust Step-Over Height (Optional)

  • The Endura aluminum sliding door panel has a patented Adjustable Step-Over feature which allows you to adjust the height of the flap to the most comfortable fit for your pet.
  • The top of the flap should be positioned to be at least 1” above the top of the pet's shoulder.
  • If the factory setting is not suitable, please adjust it before proceeding. Otherwise, proceed to the Installation Instructions section.

Step 2 Adjust the Spacers (Optional)

Adjust the Spacers (Optional)
  • Simply slide the pieces up and out from the bottom half of your panel to rearrange.
  • Loosen a bottom screw if the pieces are too snug to move.

Step 3 Reconnect the Pieces (Optional)

Reconnect the Pieces (Optional)
  • Replace the spacers and the Pet Door Assembly by sliding them back in a different order to achieve the desired height.
  • You can move the spacer below or above the flap to raise or lower the flap height.

Step 4 Retighten the Screws (Optional)

Retighten the Screws (Optional)
  • It is critical that the bottom piece is placed at the base. This is the designated attachment point for the screws. You can now assemble the patio panel.

Step 5 Align the Connectors

Align the Connectors
Align the Connectors
Align the Connectors
  • Remove the 2 flat head sectional connector screws from the exposed part of the connector on each side.
  • Align the aluminum connectors extending from the bottom flap panel section with the top glass panel section.
  • Press the aluminum connectors into the holes at the bottom of the top glass panel section.
  • Ensure locking cover & height adjustment locks are on the same side.

Step 6 Assemble the Panel

Assemble the Panel
Assemble the Panel
Assemble the Panel
  • Gently tap the bottom surface of the panel against the ground to completely insert the connectors.
  • Protect hard surfaces to prevent scratching.
  • The components of the panel are designed to slide together very tightly.
  • Fasten the two panels together using the four flathead screws.
  • Use the included flathead screwdriver to tighten all four flathead screws so the two halves of the door are pulled together.

Step 7 Loosen Height Adjustment Locks

Loosen Height Adjustment Locks
  • Loosen the height adjustment locks at the top of the pet panel with the screwdriver. This allows the spring mechanism to move freely up and down.

Step 8 Test Fit the Panel in Your Track

Test Fit the Panel in Your Track
  • You want to put the pet door in your track before applying any weather stripping to ensure it fits. If the panel fits well, proceed to the next step. See the Troubleshooting Section if you encounter difficulties.
  • To insert the panel into the top track, push up against the spring mechanism and swing the bottom of the panel up and over the threshold.
  • Seat the panel on top of the small guide rail in the track.
  • If you can't quite get it in the track, try swinging in from the outside as the outside track wall may be shorter.

Step 9 Apply Weatherstripping

Apply Weatherstripping
Apply Weatherstripping
Apply Weatherstripping
  • Once you're sure the panel fits, remove it from the frame and lay it on its side on the ground.
  • For foam weatherstripping: Peel the backing off the foam weatherstripping. Press it along both edges of the panel, trimming as needed with scissors to ensure a snug fit.
  • For rubber weatherstripping: Clean the edge of your sliding door or window with rubbing alcohol to help the weatherstripping stick properly. Starting at the top or bottom, peel and press the strip into place with the folded edge facing indoors—align angled cuts if you have two pieces. For best results, apply the seal to the sliding door or window, but it can go on the pet door panel if needed.
  • Foam weatherstripping is applied onto both sides of the panel, but the rubber weather stripping only applies on the side of the slider door. Your panel will come with one type of weather stripping. You do not need both types.

Step 10 Install the Draft Stopper

Install the Draft Stopper
Install the Draft Stopper
Install the Draft Stopper
  • The center post weather seal strip (draft stopper) should be installed on the inside of the home.
  • It can install on either the back edge of the sliding door panel or the leading edge of the stationary panel.
  • This strip prevents air from leaking between the sliding glass door and the stationary panel.
  • Trim with scissors as needed. Clean the edge of your patio door with rubbing alcohol before installing to assure a good seal.
  • Repeat step two to install the panel in your track.

Step 11 Install the Panel

Install the Panel
  • If you haven't already, insert the panel back into your sliding door track the same way you did earlier: pushing up against the spring mechanism and swinging the bottom into place. Push it snug into the side track!
  • Make sure everything is sitting securely.
  • Tighten the height adustment locks in the spring mechanism.
  • And that's it! Your pet door is installed and ready for use. Now, watch your pet strut through their new door like they own the place!
Videos

Videos

Endura Flap High-Quality Design


Endura Flap Impact Test


Leaf Blower Test


Variable Magnetic Resistance


How to Remove Side Magnets for Easier Use


FAQs

FAQ

Reviews

Customer Reviews