12 PCS Clear Plastic One Way Aquarium Air Pump Check Valves Non Return for Fish Tank

• Air check valve: great one-way check valve for aquarium and fish tank, put in the airline tube between air pump and aquarium water to prevent water from returning down the air line
• Material: made of durable clear plastic, great resistance to water; Please use a paperclip to poke it from Input side to output side when the outlet inside gets stuck
• Air hole diameter: 3 mm/ 0.12 inch; Overall size: 42 x 13 mm/ 1.65 inch x 0.51 inch (L x Max.D); Compatible with standard aquarium air pipe of 4 mm inner diameter
• Safety precaution: as a preventive measures in case the power goes out, protect you air pump by preventing aquarium water from back siphoning
• Package content: 12 pack clear black plastic aquarium check valves, small and compact, it is easy to install, good to make a brake bleeding device

Features: Plastic aquarium check valves Made of durable clear plastic, small and compact, great resistance to water Air hole diameter is 3 mm, compatible with standard aquarium air pipe of approximately 4 mm inner diameter, easy to install. Functions: The check valves fit for aquarium or fish tank, a safety precaution to protect you air pump by preventing aquarium water from back siphoning during a power outage. Specifications: Material: plastic Color: clear, black Air hole diameter: 3 mm/ 0.12 inch Overall size: 42 x 13 mm/ 1.65 inch x 0.51 inch (length x max. diameter) Packing List: 12 * Clear plastic check valves