Each Set Contains Color Coded Hose Assemblies: A Blue Service Line and a Red Emergency Line;The Service Line (Blue Hose) carries air that is controlled by engaging the foot brake or trailer hand brake.;The Emergency Line (Red Hose) supplies air to the trailer air tanks and to the emergency brakes in the event of loss of air in the system.;Our Hose Retains Coil Memory and Flexibility at Temperatures Down to -40F (-40C).;12 Galvanized Steel Spring Strain Reliefs prevent excess bending at connection ends

• 15Ft Truck Trailer Power Air Brake Lines Stay Flexible to -40F 1/2 Brass Fittings

15Ft Truck Trailer Power Air Brake Lines Stay Flexible to -40F 1/2 Brass FittingsMilspec