Replacement Inboard Ignition Coil - Compatible with MerCruiser Thunderbolt IV and V Ignition Systems with HEI - Replaces 18-5438, 392-805570A2, 392-7803A4, 392-805570A1, 72115, 40511 sold2020 1/4-18 female NPT inlet threads

1/4-18 female NPT inlet threads

and in industry

Note: The visor extender can block car lights

Simple and convenient to install

Replacement Inboard Ignition Coil - Compatible with MerCruiser Thunderbolt IV and V Ignition Systems with HEI - Replaces 18-5438, 392-805570A2, 392-7803A4, 392-805570A1, 72115, 40511 sold2020 1/4-18 female NPT inlet threadsReplacement Inboard Ignition Coil Compatible with MerCruiser Thunderbolt IV and V Ignition Systems with HEI Replaces 18 5438, 392 805570A2, 392 7803A4, 392 805570A1, 72115, 40511 Product Features Replacement Inboard Marine Engine Ignition Coil The ignition coils or ignition coil plug provides spark for your engine. Over time the factory ignition coil packs can fail, leading to hard starting, losing power when the engine is hot, or your boat may run