uxcell Plastic Aquarium Air Line Straight Tubing Valve Connectors Clear 2mm Dia 50 Pcs Protect you air pump by preventing aquarium water from back siphoning during a power outage Fit for Hose Diameter : 4mm/0.16";Material : Plastic Color : Clear;Product Name : Aquarium Air Valve Connector Net Weight : 18g;Overall Size (Approx.) : 23 x 4.4mm /0.9" x 0.17" (L*OD) Package Content : 50 ( +/-2%) x Air Valve Connector