Attwood’s multi-layer Primer Bulb provides the absolute best combination of performance, reliability, safety and compliance to ensure a safer, more enjoyable experience on the water. The patent-pending multi-layer Primer Bulb provides up to 60% more priming output than leading competitors in extreme conditions, while also exceeding new EPA requirements to prevent fuel evaporation. The exclusive 3-layer design ensures high output in temperatures ranging from 18°F to 122°F—plus resists collapsing and hardening. The inner expansion ring ensures the Primer Bulb won’t collapse during engine operation. Dual high-efficiency check valves prime in any orientation with low-restriction fuel flow that ensures proper engine operation.