Ronstan RF4055 ClearStart 50mm Sailing Watch - Blue/Grey [RF4055B]RF4055 ClearStart 50mm Sailing Watch Blue Grey Innovative Race Functions with Bold Styling Ronstan has taken the popular 50 mm (2") size and features you love and added more durability, comfort, and ease of use to our design. Ronstans ClearStart race timer and watches combine contemporary styling with true sailing functionality. They feature large buttons, easy to read displays and advanced intuitive programming designed specifically with the racing