PetSafe Staywell Original 2-Way Pet Door

Offers a simple way out for your animal Easy to install For dogs as much as 45 kg Plastic locking closing panel for protected closing when not in usage Suitable for doors of any density with optional tunnel or consumer provided tunnelSuitable for any door, wall or partition (although extra materials might be needed). Nevertheless, for safety factors it is not recommended to fit the products to glass. Cut out sizes (height x width) for wood, PVC/uPVC, metal doors: Little: 185mm x 158mm (7 1/4" x 6 1/4")Medium: 281mm x 237mm (11 1/8" x 9 3/8")Big: 370mm x 314mm (14 5/8" x 12 3/8").