The bleeding key is suitable to drain or remove air blockage from the radiator. For easy movement in tight spaces. for metal water tap and radiator usage. The structure is tight and can prevent explosions, thus can guarantee safety when you use it. Fine workmanship and creative appearance ensure its popularity and practicality. Features - Color: Silver. - Material: Zinc alloy. - Size: 2.50X2.50X1.00cm/0.98X0.98X0.39inch. - Our radiator keys are made of zinc alloy, not easy to break and bend, good compatibility, durable, can serve for a long time. - The structure is tight and can prevent explosions, thus can guarantee safety when you use it. - The bleeding key is suitable to drain or remove air blockage from the radiator. - It is manufactured with professional technology to ensure the of the product and can work for a long time. - Fine workmanship and creative appearance ensure its popularity and practicality.Packing list: 8 x Heater Bleed Keys