Specification: Item Type:InlineRadiatorHoseFillerNeck Material: T-6061 Aluminum (Surface Polishing) Inlet Hose Size: 1-1/4in Outlet Hose Size: 1-1/4in Hose Fitting: 110 mm long (neck welded to 32mm tube) The Function of Radiator Hose Filler Neck: To facilitate the addition of coolant to maintain the normal working temperature of the engine. During the long term use and driving of the radiator, the high temperature of the engine will be caused by the lack of the car coolant. Serious conditions may cause damage to the radiator and overheating of the engine, further causing various failures and affecting driving safety. Therefore, the existence of the filling port of the car radiator can easily add coolant, replenish and adjust the cooling system of the car in time, and protect the normal operation of the engine. Package List:1 x InlineRadiatorHoseFillerNeck (with Cap) Note:Professional installation is strongly recommended