Centek Marine Vernatube fiberglass exhaust tube. 4.5" x 5' x .140 wall thickness. Vernatube fiberglass marine wet exhaust tubing. Filament wound with resin impregnated continuous rovings for optimum strength. The smooth resin rich I. D. provides minimal resistance to water and gas flow while the precise O. D. facilitates easy use of rubber exhaust hose connections. Vernatube can be installed with either gasoline or diesel wet marine exhaust systems.