Product Name : Aquarium Air Valve;Hose Connector Diameter : 5mm / 0.2" Overall Size(Approx) : 47 x 23mm / 1.9" x 0.9"(L*W);Material : Plastic Color : Gray Weight : 39g Package : 20x Aquarium Air Valves The air valves are for fish tank aquarium use. Help to increase oxygen and keep air fresh, create healthy environment for your fish. Easy to connect hose. Note:Light shooting and different displays may cause the color of the item in the picture a little different from the real thing.The measurement allowed error is +/-1-3 cm.