Quicksilver primer bulbs prevent airlocks in your marine fuel system, ensuring a consistent and reliable fuel supply, especially when starting the engine. The primer bulb construction and material features three layers of low-permeation rubber for strength, durability, and longevity, and will remain pliable and functional to temperatures of 5 degrees F (-15 degrees C). They include hose clamps and are EPA-MERC-PB15 compliant.