Description: Shields Rubber Marine Exhaust Elbows 4" Id, 45 . Exhaust hose elbows let your wet-exhaust line make tight turns without kinking. They provide excellent tolerance to engine heat, vibration and back pressure. Install over rigid tubing or pipe using the four included stainless T-bolt clamps (two at each end). Not intended for hose-to-hose connections. Lubricate with water or detergent. 250F max. continuous operating temperature.