Robinair (69036A Enviro-Guard Hose Set with 45&deg; Quick Seal Fittings - 36", Set of 3 Enviro-Guard residential A/C service hoses feature a special barrier material that prevents virtually any permeation of refrigerant - ideal for use with R-410a and other high pressure systems Set of 36 inch long, 1/4 inch yellow, blue, and red hoses; 740 PSI working pressure; 3700 PSI burst pressure Brass 'Quick Seal' fittings - 45 degree on one end, straight on the other - provide a leak-free seal Coupler nuts feature deep knurling for a positive grip that enables quick finger-tightening Hose ends feature a strong six-sided crimp that provides a secure, reliable connection between the hose and barb - even at maximum pressure