Manual or automatic feeding: Automatic mode can set the time reasonably, feeding every 12 hours or every 26 hours, helping you feed automatically when you are on vacation or on a business trip. Meanwhile, one-click manual feeding will not affect the preset times. Two installation methods: for open aquarium, fix the feeder with the clamp, install it on the wall glass of the aquarium; For closed aquariums, attach the Velcro on one side to the aquarium lid, the other side to the base of the feeder and glue the two sides together. (Note: When using Velcro, you need to wipe the surface, then fix it and finally install the feeder.) Food type selection: This timer feeder can only be used for food dry. Ideal for pellet, strip and flake fish food. Please place it above the upper tank to protect the food from moisture. Then attach the tank cover leaving only one hole. Put some aquatic plants in the hole, drop the food into this hole, and the fish will come and eat the food. Operates with 2 AA batteries (not included): When you clean the food box, remove it Simply rinse thoroughly with lukewarm water and clean the drum. Make sure the drum is completely dry before adding food.