Sized for medium dogs up to 40 pounds, this sliding glass pet door swings open a full 180 degrees in either direction, so you can push carts, bags, or bulky items straight through instead of working around a narrow flap. It adjusts with a turn knob to fit door heights between 75 7/8 and 80 11/16 inches, covering most standard sliding glass and patio doors. High-density felt weatherstripping lines both sides of the frame and flap to block drafts and keep conditioned air from escaping around the edges, which helps keep the room next to the door more comfortable. The flap rides on premium metal hinges designed to resist warping and sagging even with frequent daily use from an active dog. Note that this size requires drilling a few holes into the door frame during setup, so plan for a short installation rather than a fully tool-free one.