MG Superduster Chrome Plated Trigger Valve is a professional valve for use with MG-402AR Super Duster 134 Refill canisters. Allows user precision control and greater comfort. This high quality threaded chrome valve can be used over and over. It simply screws onto the top of the can, and can be easily removed at any time later without damage to the valve or the can, even if the can's contents have not been depleted. When used instead of standard valves, the Trigger Valve gives the user better control of flow, a higher maximum rate of flow, and increased comfort.