This is 1/4" Brass Mini Ball Valve.Ball valves use a spherical disc to control the flow between pipes, tubes, or hoses. It is made of forged brass for higher corrosion resistance than steel and has a plastic-covered lever handle for on/off manual control. Do not over tighten. Can be used to give your tool full air flow to total shut-off. Designed for use on all pneumatic circuits and features a quick connect/disconnect positive seal.