Features: If you only have a pump, but there are several small fish for tank needs encouragement, how do you Select the pipe tee It can be used to pipe into two groups for various pump equipment increased supply capacity or other purposes. Separable cylinder oxygen pump, for valve and pipe supporting the use of oxygen good effect. Usage: Tee outlet ends of the inlet end, a direct oxygen tube can make a gas stream becomes two shares. The connector for connected between tube (pipe) for flow of air, oxygen, oxygen pump, water Diameter: Outer = ?5 mm. (use with tube diameter Inner = ?3 mm) Specifications: Color:Transparent Material: Acrylic Quantity:10Pcs Package Includes: 10 Pcs Plastic Control Valves note: 1.Please allow 0-1cm 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!