Rational Design: This auto oil dye injector is designed with a 1/4" SAE female fitting that easily connects to a 1/4" SAE male system port for easy handling and convenience. Filler: 30ml (1oz). Strong Compatibility: This car oil injection tool is designed with a 1/4" female connector, compatible with most AC systems, compatible with fluorescent dyes for leak monitoring, and compatible with all oil types (POE or mineral oil), as well as with all refrigerant types for a wide range of applications.