5pcs Fish Tank Air Check Valve Plastic Non-Return One Way Check Valve Aquarium Air Pump Protectors Practical Fish Tank Accessory

【APPLICATION】 - Aquarium air check valves are suitable for standard 4mm airline hoses and all common aquarium air pumps, but NOT suitable for CO2 system. It's a very friendly aquarium air pump accessories for the oxygen aerator.【FUNCTION】 - This aquarium check valve for aquarium air pump can protect the air pump, preventing the aquarium water from back siphoning into the air pump during a power outage, which will damage and shortened the lifespan of the air pump. This one way air valve is perfect for aquariums and fish tanks.【TROUBLESHOOTING】 - If the outlet inside of the aquarium air valve gets stuck, please use a toothpick or paperclip to poke it from input side to output side.Product Name: Aquarium Air Check ValvesMaterial: PlasticColor:RedSize: 5.5cmQuantity: 5pcsPackage Included:5pcs x Aquarium air check valves