Review on Premium Endura Flap Pet Door: Double Flap, Extra Insulated for Cold Weather, Aluminum Frame, Indoor/Outdoor, Easy Install - Sizes: S, M, L, XL - White, Tan, Black by Jessi Hodges

GREAT product! I've opened boxes at local pet stores before. there is no comparison. I will certainly say the cost is more than I would like to pay but I will not say the cost is high compared to what you can find at your local pet store. As others have pointed out, you will end up with a paper cut that is too large. over an inch. I realize they do this because they are not going to drill four separate bolt holes holding the two doors together. We didn't order a custom door until we received the Endura flap, so I was able to give an approximate opening of up to 9 1/2 x 18 1/2, which I think would be ideal. In order to mark a hole of this size, I had to drill four holes. If you're not precise with that, I could foresee the headache in many ways. (Bolt Alignment, Leveling) I used the supplied material to create the "Tunnel", I'm not sure if it was necessary but I did it anyway. The finished end product was fantastic. Perfect! Our beagle weighs 22 pounds. in and out the door in less than five minutes. We set the cutout 3 1/2" from the bottom of the door, I might have chosen 3" if I had to do it all over again. We opted for a double flap. I don't know how the single valve version works. I couldn't imagine not having dual valves. Great purchase, glad I did the research I did before as there is no comparison. Update: June 29, 2015 Almost a full year later and still runs like new. Our beagle ran through that door at least twenty times every day. The dog pushed anything you could think of through the valves and they held up very well. Once or twice if the dog did this with a large blanket or branch the seal would come loose causing one of the flaps to become tangled, but it's easy to reattach the rubber. The magnets hold up well. Like I said I couldn't think of a single valve, double valve is excellent. The only minor downside, as mentioned by some, is the noisy action. You can't hear it during the day. adjust like we do, give the dog more freedom at night when it's quiet around the house you can clearly hear the flaps snapping in and out. (keep going ;) my dog seems to be nocturnal)