I am so glad that I bought this cat flap. I have had it placed in an inside door which I want to keep closed due to a draft. I didn't install it myself, but it was easy to install with three parts to it. The steel frame is well made and the flap closes with a magnet built into the frame. At the moment, my four cats have got used to going through the hole without the flap attached, have had paper instead of the flap, so they get used to pushing something and now have progressed to pushing card instead of paper. I am going to put the flap on tomorrow and see how they go. I am very pleased with this product. It has already made a big difference to the warmth in my lounge/dinning room. I thoroughly recommend this cat flap. Thanks!