This window-mounted cat door slides into place without drilling - you simply set it in the window track, tighten the adjustment knobs, and it's ready to use. A 5-inch adjustable length lets it fit window openings between 31 and 36 inches wide, and the 7.6 x 10.3 inch flap gives most cats an easy, unforced passage in and out. Four lock settings let you switch between in-only, out-only, two-way access, or a full lock, so you can manage when your cat comes and goes without watching the door yourself. A magnetic flap paired with a brush-lined edge closes quietly and seals tightly enough to keep drafts and outside noise from creeping into the room. The aluminum alloy frame and clear, scratch-resistant flap handle a cat pushing through several times a day without the frame loosening or the flap clouding over. Measure your window track before installing to confirm it falls within the adjustable range.