Robinair 72 inch Blue Enviro-Guard Hose for R-134A"s premium refrigerant charging hoses are built for long life and dependability. A strong, six-sided crimp provides a reliable connection between the hose and barb, even at maximum pressure. The coupler nuts are deeply knurled for quick finger-tightening. The Enviro-Guard hoses are ideal for high pressure applications. 72 inch Blue replacement hose. It meets all specifications for low permeation construction. It is clearly marked for R-134a; 740 psi working pressure and 3700 psi burst pressure.