Efficient, Effective protection for your pump Great one way check valve for aquarium air pump. Non Return anti syphon valves to protect your electrical equipment. (air pumps etc) 100% new and high quality One way Length: about 3.5cm/1.38 inch Type: fish Tube Calibre: 0.5 cm Power: 1W colour:blue Material:plastic Size:Approximately 3.5cm Package Contents: 100 * Aquarium check valve Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.