I got the self locking too. And I'd also want to do the timer rather than the automatic light sensor. I just don't like not having control of that variable.I just installed the standard version of the chicken guard on my coop, I got it as a bundle with the self locking door kit. Its not the cheapest but it works very well and was very easy to install and set up. I went for the standard one because I don't think I would use the automatic light sensor to open and close the door, I prefer letting them out later in the summers so they don't upset the neighbours at 6am.