3M™ Performance Spray Gun Ball Valve is an accessory for the 3M™ Performance Spray Gun System configured as a pressure feed sprayer. The valve gives the spray gun operator the ability to stop the flow of paint from the pressure source (pot or pump) at the spray gun end of the supply hose. Recommended for use when the painter does not have easy access to the pressure source. Light and easy to use.The addition of a 3M Performance Spray Gun Ball Valve allows a painter to quickly stop flow of liquid to the 3M Performance Spray Gun when the spray gun is set up as a pressure feed sprayer. This valve is recommended whenever the painter cannot easily access the pressure source (e.g. on a ladder or a long distance away).