You are looking at a brand new Large 2 oz Compressor Oil and/or Fluorescent Dye Injection Syringe/Injector/Charger , for AC/HVAC/R Professional Services; One Shot May Save A Sickened Compressor! Why oil injector is needed? Answer: Compressor oil in a compressor of any refrigeration systems, gets pumped along the refrigerant through the whole system, and get to a "balance" if the return of the oil to the compressor is not restricted and the suction line is configured right... How the compressor oil is added? Answer:Use an Oil injector like this one, to add the oil to the refrigerayion systems. First, extend the cylinder... What is the difference between screw-in type injector and in-line injector Answer: Inline injectors use the system compressor as the power source to force the content into the system, screw-in type injector use human power to force the content into the system by twisting the cylinder ... See the answers at: https://viot.us/showFAQ.php?model=OI2 FEATURES: 2 oz capacity; Good for compressor oil or fluorescent dye; One shot may be it all takes to cure and save a sickened compressor caused by low oil; Compatible with fluorescent dyes for leak monitoring, too Compatible with all oil types(POE, or mineral oil) Compatible with all refrigerant types, including R410a R22 R134a etc. Re-loadable, re-usable, keep it in tool box for decades to come. Aluminum alloy body, brass connector, high pressure hose. 1/4" female connector, make it compatible with most AC systems. 45 degree turn at the connection, easy to access port. 5 inch flexible high pressure hose. Hand operated(Screw-down), NOT in-line injector, do not need other power. In stock and ready to ship. Buy it now for only $49.97; please take a look at the other listings of HVAC service tools in my eCRATER store, more information available at https://www.viot.us, Scan this code with your mobile device to buy it now: Scan this code with your mobile device for more deals: VIOT, located in Champaign IL, is proud to be an alternative source for quality HVAC tools serving the HVAC community for almost a decade . Here is a partial list of what we supply: Vacuum pumps, from 1.5 CFM to 12 CFM, single stage and dual stage, over 10 models to choose from, Clamp meters and multimeters, more functions get the job done easier. Halogen and gas leak detectors, find the hard-to-find leaks and fix it, Refrigerant Recovery Unit Weather monitoring tools: hygrometer, thermometer, wind speed meter Manifold gauges, manometers for system diagnosis Oil and Florescent dye injectors Tubing tools, tube cutters/benders Valve tools, valve core remover/installer, Ratchet wrenches, valve cores and add-on valve/service port. Car AC attaching /recharging tools, quick connectors Temperature/Humidity sensors and monitoring devices. Motor start/run capacitors, 5 MFD to 50 MFD, dual capacitance available. AC and AC Tool parts, accessories, etc Check with us for specials and discounts often. They change from time to time