Value for money: 2 square ring + 2 round ring, square: 10 * 10cm, round: outer diameter 8cm, to meet your needs. Buoyancy ring: The back of the feeder is a safe suspension foam, which can make it floating the water, controls food dispersal to reduce food waste. Easy to install: Each Floating food circle has a silicone suction cup, which can be fixed on the wall of the fish tank or other smooth containers. High-quality materials: The entire feeding ring is made of safe materials, Dont worry about polluting the water and prevent food from entering the filter. Application: The fish feeder is suitable for feeding flakes, pellets or other floating foods for goldfish and other small fish Specification: Material: high-quality safe plastic + environmentally friendly suspension foam Quantity: 4 (2 square ring + 2 round ring) Advantage: Control food dispersal Reduce food waste Keep the water clean Prevent food from entering the filter Classification feeding How to use: 1. Install and fix the suction cup on the wall of the fish tank. 2. Put the feed in the feeding circle. Note: Due to manual measurement, there may be a small error of 0.5cm-1cm, thank you for your understanding.