"I love my patio doggy door. My dogs took to it within the first 3 hours of it being installed. I just wish it came with thicker weather stripping(don't order the recommended kit, it's not made for patio size door). My dogs are 10-15lbs and the medium door is perfect. I am getting a second one for my other patio door. Tip: too make it easier for training, tape the flap magnent down until the dog gets used to using door."