?If you are looking for a non-return check valve£¬ you should choose the one we serve here. The Cylinder Non-return Check Valve for Aquarium Air Pump is designed for connecting to your air pump or air driven system. It is a backflow prevention device specially designed to prevent water contamination. The cylinder non-return check valve for aquarium air pump ensures the air to pass in only one direction£¬ which protects your pump from accidental power loss. Come and check it out£¬ you will not regret to buy it!                                    Features            Top quality material and low resistanceProtect you air pump from back siphoning during a power outageSmall and compact£¬ very easy to useA necessity for your aquarium water cleannessReasonable price for good quality                                                            Specifications            Color: WhiteMaterial: PlasticDimensions: (2.08 x 0.59)" (5.3 x 1.5)cm (L x Dia)Weight: 0.04 oz / 1 g                                                            Package Includes            1 x Cylinder Non-return Check Valve for Aquarium Air Pump