I am new to the automatic door group. But, I am building my chicks a new coop and figured to give it a try. I will say, like others, that the instructions sure are lacking. When instructions say "about" 12 11/16", that doesn't seem to be an "about". I am not an engineer but was able to figure out how it really should be installed. I do wish it had a switch on the control box so that it can be closed without the remote. I thought I had an issue with the light sensor, but it seems to be working now. Other reviews have suggested to buy the 27A batteries when you purchase this, THAT was the best advice. I bought a 2 pack for under $4 and you do NEED them. Seems the company could include them in the kit, even if they charge a few bucks extra.