【Check Valves】 The check valves are suitable for common aquarium air pumps. Note: Please DO NOT use them with CO2 system. Great one way check valve for aquarium and fish tank.
【Function】 The check valves just to protect you air pump by preventing aquarium water from back siphoning during a power outage.
【Stable&Light】 The check valves are made of durable clear plastic. just 0.14 oz / 4 g. Note: Please use a paperclip to poke it from Input side to Output side when the outlet inside gets stuck.
【Size】Air Hole Diameter: 0.15" / 4mm; Overall Size: 2.1" x 0.58" / 5.3 x 1.5 cm (L*Max.D)
【Package Content】 20 x Air Check Valve , 1 x 25 feet Airline Tubing
