Heavy duty aluminum 2 oz. refillable dye and oil injection system. To inject dye or oil, simply connect the injector to the low side of the A/C system and twist the handle until you reach the desired amount. The injector hose comes complete with a R-134A coupler and Auto Shut-off Valve Adapter for 1/4" FL systems. Injector easily allows the user to inject any dye or oil into any R-12 or R-134A system.