If you're tired of being your pet's full-time doorman, this dog door is about to change your life! It's designed for medium-sized pets up to 40 pounds, with a frame that measures 11 5/8 inches wide by 16 7/8 inches high, and the actual flap opening is 8 3/4 by 12 1/4 inches. The whole thing is made from super sturdy plastic that can handle whatever your pet dishes out. It comes with magnetic flaps that close quietly and securely after your pet goes through, plus there's a sliding lock panel so you can lock it when needed. The installation is pretty straightforward - it comes with a cut-out template and step-by-step instructions, and it fits most doors between 1-2 inches thick including wood, PVC, metal, and paneled doors. Your dog or cat will love having the freedom to go in and out for potty breaks or just to enjoy the outdoors without bothering you every time. It's also energy-efficient with a tight seal that helps keep your heating and cooling bills in check. The white color looks clean and blends well with most door styles. We're so confident in the quality that we offer a lifetime guarantee - if anything's missing or breaks due to manufacturing issues, we'll replace it no cost to you. Seriously, this little door means more freedom for your pet and more peace and quiet for you - it's a win-win!