Robinair Premium Refrigerant Charging Hoses are built for long life and dependability. A strong, six-sided crimp provides a reliable connection between the hose and the barb, even at maximum pressure. The coupler nuts are deeply knurled for quick finger-tightening. Enviro-Guard Hose Quick Seal Fittings prevent any refrigerant loss when disconnecting hoses from fittings eliminating harmfull refrigerant burns.