The heart of any pet door is the flap, and pet door flaps have always been a big disappointment to the pet door owner. They leak, they don't insulate, they pinch the pet, they blow open, they don't fit the pet and they wear out quickly so the user needs to buy an expensive replacement flap and start over again.

Some have been better than others in one respect or another. But none has ever succeeded in achieving superior performance in every respect. This is particularly true of the brands that are most heavily marketed today.

Beginning in 2001, Patio Pacific, Inc, undertook an intensive engineering design effort to build the perfect pet door flap and, based upon that design, to produce a full range of superior pet door products. By Fall of 2004,  that work had culminated in the "Endura" Flap Assembly.

The rest of these pages are devoted to a presentation of the patented Endura Flap Assembly design through a discussion of the major design criteria.

If you've ever owned a pet door, you're going to love what you see here.

Note: False colors are used throughout in these engineering drawings to emphasize various components of the flap design.