Mercury - Pitot/Speed Sensor Kit 100 PSI SmartCraft Speed Input 881879A13. Overview. For boats that run under 80 mph and rely on SmartCraft for speed data, this kit makes the whole setup easier and more complete. The Mercury 881879A13 Pitot/Speed Sensor Kit delivers a 100 PSI water-pressure speed signal and includes the harnessing needed for today's 10-pin rigging layouts. It mounts cleanly on the MerCruiser sterndrive transom bracket or directly on the hull near the engine, giving SmartCraft ga