Features: Oxygen is an essential air for fish to live in the fish tank, and this type of air pump is used for atomizing oxygen.This device will make oxygen more small and will improve the oxygen amount in fish tank.Silent,mini size and ultralight.Bubble size can be adjustable and easy to control. Specification: Material: Plastic Type: Round Note:1.Please allow 1-3cm error due to manual measurement. pls make sure you do not mind before you bid. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you Size: as shown Color: black Quantity shipped: 1