2 1/2" (63mm) HPS High Temp Reinforced Silicone Hump Coupler Hose 4" 4-ply Black Temperature Range: - 65 deg. F to + 350 deg. F (177 deg. C) Reinforced Layer: 4-ply Hose Inside Diameter: 2.5" (63mm), Hose Outside Diameter: 2.88" (73mm), Wall Thickness (mm): 5 Hose Length: 4" , Color: Black Silicone hose is compatible with water or anti-freeze such as coolant.Silicone hose is NOT compatible with fuel or oil.