The most important criteria when selecting a compass are dial size and mounting style. Quality components aid accuracy, smooth response, stability and trouble-free operation. RITCHIE NAVIGATION's Explorer Compass B-51G is for marine/automotive use and is Gray with a blue Direct-Read dial. This compass is easy to install on your marine/automotive vessel's windshield or dash! It features 2-3/4" Direct-Read dial, internal green NiteVu illumination, powerful Directive Force magnets for fast heading lock-on, Hardened Steel Pivot Movement, Sapphire Jewel Movement and high temperature composite construction for extended operating range. Included are built in compensators and a movable sun shield. This compass is 100% repairable and has a 5-year warranty.