Product Upgraded from manual version and automatic feeding Increased 3 different timer setting modes, 8h/12h/24h, unlike other suppliers 2 modes. The feeder also has a Manual button, have fun when you feed the fish yourself. Three installation modes: 1.Use the universal clamp to fix the feeder on the edge of the aquariums. 2. Tear off the protective film from the velcro and attach the charger to the top of the aquariums. 3.Add the aquarium feeder base with the hopper to install it on the aquarium. Moisture prevent design the moisture-proof hopper keeps the fish food dry, do not wont get wet or stuck. It can accommodate most types of feed, including flakes, pellets or crumbs. Two Size Feeding Boxes This fish feeder has a two size feeding box for 50g or 100g fish food different aquariums, you can choose the right food box according to your needs. USB or battery powered It can work with USB charger and battery at the same time. 2 x 1.5V batteries, when the battery is inserted and connected by USB, the automatic fish feeder will automatically change to USB model.