Robinair (62121 Enviro-Guard Hose for R-134a - 96", Blue Enviro-Guard automotive A/C service hoses feature a special barrier material that prevents virtually any permeation of refrigerant yet still remains flexible 96 inch long, 1/4 inch blue hose is clearly marked for R-134a and features a 500 PSI working pressure and 2500 PSI burst pressure 14 mm male x 1/2 inch ACME female fittings Hose ends feature a strong six-sided crimp that provides a secure, reliable connection between the hose and barb - even at maximum pressure Coupler nuts feature deep knurling for a positive grip that enables quick finger-tightening