Sierra Shields Marine ExhaustWater Hose 2-12 Sierra Shields Marine ExhaustWater Hose 34 is made of black, heavy-walled synthetic rubber. The hose is resistant to engine heat, exhaust fumes, ozone, mild chemicals, antifreeze, and saltwater. Features Reinforced with 2 plies of synthetic cord Made of black, heavy-walled synthetic rubber Specifications I.D. 2 12 or 63mm O.D. 3 or 76mm Wt. C 136 Burst Pressure 220 PSI Working Pressure 75 PSI The temperature ranges from -20F - 200F continuous, 250F in