I understand. I probably figured out more stuff once they arrived and I installed it. The starter system is all that you need. Again, screen wedge if you want to install the nozzle on the top of the cage, or rain dome if you don't want to deal with install a nozzle. The screen wedge is just a piece of plastic that allows the nozzle to be anchored better. If you do get the RCT timer, and get confused, I can definitely give you my number to call, and it will take a few minutes. I may take the time to type out some instructions, since their instrustions seem confusing until you finally understand what their terminology means.