With the Robinair 18065 Oil Injector with 1/4" SAE fitting it takes just seconds to transfer an oil charge while the system is in a vacuum. The injectors are great add-ons to recovery/recycling and charging. It installs in-line on the low side of the manifold. Made of durable polypropylene with oil levels marked in ounces and milliliters and has a solid brass fitting with a LexanŽ handwheel.