Two piece quick coupler connector adapters for R1234yf to R134a conversion. and low side connector conversion kit for AC charging R1234YF air conditioning system hose fittings. Low side (blue): R1234YF low side quick connector is 14mm female x 1/4' SAE male. R12 to R134a adapter connector: 1/4' SAE female x 13mm R134A quick connector. side (red): R1234YF side quick connector is 17mm female x 1/4' SAE male. R12 to R134a adapter connector: 1/4' SAE female x 16mm R134A quick connector. Material and durability: brass construction, strong and durable, rust resistant, not easy to break, long service life. Easy to install and remove: Autooff function makes removal and installation easier. Balllock design with a rubber seal provides sealing performance. Benefits and compatibility: Helps prevent mismatched fittings, reduces refrigerant leakage, and is compatible with common service equipment for R1234YF and R134A systems. Includes adapters to connect R12 systems to R134A service components. Use scenarios: 1) Servicing a R1234YF air conditioning system using standard R134A charging hoses and gauges. 2) Converting an older R12 refrigerant system to use R134A service equipment with the included adapters. 3) On site charging and testing for vehicles that use either R1234YF or R134A refrigerant, ensuring secure and leak connections.