EPA COMPLIANT / CARB CERTIFIED.. Multi layer bulb designed for high performance priming in the harsh marine environment. Multi-layer design prevents over-pressure bursting and vacuum collapse preventing proper fuel flow. Low permeation bulb prevents fuel evaporation saving gas and money. High performance check valves for quick priming and unrestricted flow ensuring proper engine performance and minimizing engine wear. Bulb is firm but not stiff like other newer EPA/CARB compliant primer bulbs.