A/C Oil and Dye Injector with Snap Quick CouplerSpecifications:Condition: 100 Percent Brand NewMaterial: Aluminum Alloy, Rubber, Pure CopperTank Capacity: 1/4oz/7.5ml2oz/60mlThread Size: 1/4inch SAEHow to Use:1. Check valve screwed onto cartridge and tightened. The inner and outer cylinders are tightened clockwise.2. A little 1/4 SAE threaded inner core is used to discharge a little air inside the blue tube. 3. Connect the low-pressure port of the refrigeration system that needs to be refueled.4. Add the required amount of cooling oil to the inner and outer cylinders.Note:Please wear safety goggles to avoid contact with refrigerant.Package Included:1 x 2oz A/C oil and dye injector1 x R134A snap quick coupler