Large Cat Door Interior Door, XL Indoor Cat Door, Pet Doors for Cats, Kitties and Small Dogs (Black) Rivet the length of the hypotenuse

the length of the hypotenuse is 54mm/2

and the thickness is 0

serves the function wonderfully

Widely Applicable: Measuring 55

Large Cat Door Interior Door, XL Indoor Cat Door, Pet Doors for Cats, Kitties and Small Dogs (Black) Rivet the length of the hypotenuseTEMPLATE INSTALLATION : Includes full instruction manual. Using the cutting template to cut holes in the door and use the included screws to secure the pet door in place. SAFE AND DURABLE: The indoor cat door is made of ABS material, which is wear resistant and durable. The edges are smooth and burr free to protect the cat from being scratched. Smooth line design, paintable materials, perfectly matching your door and decoration. BARRIER FREE DOOR