Mercury - Tachometer 7K Engine Speed Monitoring Black Face Chrome Bezel 79-8M6020002. OverviewThis 7,000-RPM tachometer gives you a steady, natural read on how the engine's running, even when the water gets a little messy. The needle doesn't twitch or bounce-it settles into a smooth swing that matches what you're hearing from the motor. On the water, it becomes a quick, easy check: glance down, grab the number, and you're right back to driving. It's a simple, clean gauge that fits right into eve