The Nutrafin Nutramatic 2X Automatic Feeder provides flexible installation options which allows for rim and free-standing positioning while fitting within some canopies. This easy set unit distributes food at two intervals during the day and features food quantity adjustment and anti-humidity door to protect and maintain food quality. Flakes, granules and pellets can be used with this automatic fish feeder.Nutrafin Nutramatic 2X+ dispenses flakes, granules or pellets+ feeds every 12 hours+ controllable food quantity setting+ free-standing, rim-mountable and fits in canopy+ battery operated (2 AA, not included)+ anti-humidity door