All In 1 Primer Bulb, Has Threaded Ends & Changeable Fittings To Accommodate 1/4", 5/16" & 3/8" I.D. Fuel Hose, Double Check Valves To Hold Prime Longer, Oversized Directional Bulb Works On All HP Outboard Motors, UV Inhibitors Protect It From Prolonged Exposure To Sun, EPA & CARB Compliant.