[Size]1 or 4 inch male air compressor quick plug to a female 3 or 4 inch garden hose inner thread and 1 or 4 Inch Male Quick Connecting Plug and 3 or 4 inch Male GHT Thread, this is standard size and can be applied in most cases. [Material]This RV winterize blowout adapter is made of heavy duty copper which is durable and it can withstand high temperature, sturdy and corrosion resistant. It is not easy to break or deform and can you for a longer time. [Application]Winterize blowout adapter is used to winterize garden hose, sprinkler systems, faucets, by blowing out water from the water lines or plumbing, prevent sprinkler system and pipe plumbing damage from freezing in winter. It can reduce the use of antifreeze, very Convenient, safe, healthy, environment friendly. [Easy to Use]Screw the water lines to the female or male threading side, then connect the quick plug to an air compressor line's female quick coupler. Turn on the air compressor, rotate around ball valve's stem to open or close and modulate the air flow velocity to blow out the water from the water lines. Product Usage: RV Garden Water Pipe Connection Material: copper colour: yellow Package Contents: 1 pair x RV Sprinkler Adapter Only the above package content, other products are not included. Note: Light reflection 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 1-3cm.