The ultimate tactical race compass and windshift indicator. Its two-tier display shows your heading, how far you are above or below the mean course, and how much you are being headed or lifted. It will enable you to establish quickly and easily which is the favoured end of the start line, and will help you sail the shortest distance to the windward mark. Downwind, you can see how far off dead downwind you are, and when you should gybe for optimal VMG.Features: No wires or connections to make Solar powered Twin displays with super-large digits Backlighting Totally waterproof (submersible to 10m) Shock resistant Lightweight Full calibration Specifications: Instrument Function: Multifunction Box Dimensions: 4"H x 7"W x 9"L WT: 2 lbs UPC: 723193703458 Owner&';s Manual (pdf)