Mercury - Tachometer 7000 RPM SmartCraft Analog Gauge White Face 85 mm 79-8M0052875. Overview. The Mercury Tachometer (8M0052875) gives you a clear, real-time look at your engine's RPMs so you always know how it's running. It's an easy-to-read 7000 RPM gauge with a white face, bold black numbers, and a glass lens that stays clear in sunlight or shade. It drops right into a standard 85 mm (3-3/8") dash hole and ties into your SmartCraft system for fast, accurate data. Clean, simple, and dependabl