Bought these for summer holidays. Programmable, up to four feedings a day, can set more than one rotation. I use 1 rotation, once a day for my flakes and 2 rotations for the algae discs because sometimes nothing comes out. I could break the discs for better dispersal but my fish don’t mind if they get double once in a while. Easy to program. I used them for an entire month before our holidays to ensure they would work and they worked flawlessly.