Large:2 oz Compressor Oil, Flourescent UV Dye Syringe Injector Charger, Screw-in Type Reuse Reload HVAC Automotive AC Air Conditioning Service Tool Push-in Type Compressor oil flurescent dye injector for HVAC Compressor services reloadable and reusable, remove cap to load oil and twist to push content in AC system. Add flourescent dye if you wish for leak checking. No working compressor needed to do the job Professional service tool. Scale on the side, 1/4 fitting for standard AC port Alternative for YellowJacket or other brand names for a quality tool at the better prices.