【AUTOMATIC FEEDING】Just one button push, the automatic fish feeder allows you to feed every 8hours, 12hours or 24hours automatically or feed any time manually according to your need. 【TWO TYPES POWER SUPPLY】 Powered by two AA batteries(not included) or use USB cable to connect home electricity, the 6.6 feet USB cable is included in the attachment. Also you can use two power supply at same time in case of emergency such as power outages. USB cable is the default setting, if the home power is cut off, the battery will supply power automatically. 【TWO DIFFERENT FIX METHODS】The feeder can be fixed on edge of the fish tank with a stent for aquarium without hood or fixed on the tank hood with special designed funnel base for aquarium with hood. 【TWO FEEDER CONTAINERS】Two size containers are supplied, one 50ml and the other is 100ml. Also ahttps://www.amazon.frfeeding ring is attached. 【EASY to ADD FOOD and ADJUST VOLUME】Just pushing the feeding adjusting cap to increase or decrease the