The "Endura Flap" Quick Panel III patio pet doors is identical to the Thermo Panel III except for the use of single pane glass instead of dual pane glass. It is appropriate for more temperate climates or where a lighter weight panel is desired. The benefits of the Endura Flap are far more important than whether the glass is single pane or dual pane.

The difference between this panel and the earlier Quick Panel II is that the Quick Panel III uses the new 'Endura' flap--the best performing pet door flap ever made--while the Quick Panel II uses flap assemblies made by other manufacturers.

Extreme Performance 'Endura' flap - The best performing pet door flap ever made. Tired of replacing worn out, leaking flaps? You owe it to yourself to investigate the Endura Flap. See the full story here. Want to see an example of a popular leaker after some use?

Patented, exclusive 'User Adjustable Rise': Lets the user easily adjust the height of the flap above the base of the pet door to fit taller or shorter dogs (see graphic). This greatly increases the flexibility of the pet door for the future.

Resource: http://patiopetdoors-4less.com/petpr...tio_Door.65359