Jardin 5-Piece Plastic One Way Aquarium Fish Tank Air Check Valves, Clear/Black

Jardin 5-Piece Plastic One Way Aquarium Fish Tank Air Check Valves, Clear/Black

• Package Include: 5 x Check Valve; Hole Outer Diameter: 4mm; Fit Hose Dia: 4mm; One check valve for one-way outlet, two check valves for two-way outlet, ect.
• Place your airline tubing between your air pump and aquarium to prevent water backflow to the airline.
• Protect you air pump by preventing aquarium water from back siphoning during a power outage.
• Please use a paperclip to poke it from Input side to Output side when the outlet inside gets stuck.
• Use hot water to soften the hose first, it can be connected to the check valve more easily and tightly.