Features and Benefits:Sturdy Aluminum ConstructionAdd Oil/Dye to R134a/R12 SystemsAuto Shut-Off AdapterInjector Marked with .1 oz., 1/4 oz., 1/2 oz.Excellent method for adding refrigerant oil or large amounts of UV leak detection dye to the A/C system.To inject the oil or dye, 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 13mm-M x 13mm-F Low-Side Coupler (R134a) and auto shut-off valve adapter for 1/4" FL systems. Includes 2oz/25 applications AC universal dye.