This sliding glass pet door is built for large dogs up to 100 pounds, with a 10 1/4 x 16 1/4 inch flap and a panel that swings open a full 180 degrees in either direction. That wide swing means you can carry bulky items, a laundry basket, a bag of dog food, a stroller, straight through the opening instead of maneuvering around a narrow flap. It adjusts to fit door heights from 75 7/8 to 80 11/16 inches using a turn knob, and installation requires no drilling, so it slides into the existing track and comes back out just as easily if you move. High-density felt weatherstripping runs along both the inside and outside of the frame and flap, sealing out drafts and keeping hot or cold air from leaking in around the edges. Premium metal hinges are built to handle an active dog's frequent in-and-out trips without warping or sagging over time.