Mercury - SmartCraft Gauge Housing Fits 85 mm Gauges 8M0099412. Overview. The Mercury SmartCraft Gauge Housing (8M0099412) is designed for applications where a traditional dash isn't available - like tiller or transom-mounted setups. It provides a secure, durable mounting solution for 85 mm SmartCraft gauges, including System Tachs, System Speeds, MercMonitors, and SC100 Link gauges.. Built from marine-grade materials, this housing is rugged enough to handle years of vibration, UV exposure, and