The Robinair 18465 is a PAG labeled manual oil injector that enables the user to inject PAG type A/C system lubricant back into the vehicle's A/C system. The 18465 injector holds 1/2 ounce of oil and includes graduations on the injector in 1/8 ounce increments. The injector is equipped with a low-side R-1234yf service coupler that allows the user to connect to the low side of the vehicle's A/C system. Oil can be injected either before charging or after charging the vehicle's A/C system.