Set of 3 Screws (Old Style) for Large Size
To determine the correct size door, simply measure the width (A) and height (B) of your pet.
(A) Measure the widest point of your pet's shoulder.
(B) Measure from the top of your pet's back (just behind their head) to the bottom of chest.
Pet door models have different size openings. Just make sure your new pet door's opening is both wider and taller than your pet's measurements to ensure they can comfortably pass through.
