Exhaust Waterlocks various sizesHeavy duty black polypropylene construction suitable for wet exhaust systems only. These waterlocks prevent water from flowing back to the engine and they reduce exhaust noise. They have the facility for either top or side entry by cutting the desired port. Colour coded. Red Suits 38mm (1 1 2") hose Black Suits 44mm (1 3 4") hose Blue Suits 50mm (2") hose