I’ve used this feeder for about a month. It is very easy to set up, but you will need to read the directions. I tried to set it up without the instructions and I couldn’t figure it out. You need D size batteries. If it came with an AC adapter I would give it another star. For the price, I believe it should come with one. Anyhow, my cats love it and very quickly learned how to tell time and began lining up a few minutes before it dispenses.