Mercury - Trim Gauge Black Face 2-1/8" (52 mm) 8M0206585. Overview. The Mercury Trim Gauge (8M0206585) makes it easy to see your engine's trim position at a glance. Whether you're trimming up to plane faster or dialing in for smooth cruising, this gauge gives you quick, accurate feedback. It features a black face, crisp white markings, and a glass lens for clear visibility in all light conditions. Designed to fit a standard 2-1/8" (52 mm) dash opening, it integrates seamlessly with SmartCraft-eq