Windex 10 C will be the perfect choice for smaller cruising and racing boats from 3-6 meter (10-20 feet). Windex wind vanes for sailors that need exceptional performance at the best value of any wind indicator worldwide. The secret is in the sapphire jewel suspension bearing, large fin-low inertia vane, and easy-to-read, fully adjustable tacking tab system. Reflector tape on the vane and tacking tabs make Windex 10 easy to see day and night. Windex vanes are sturdy and when installed properly, offer many years of use. They have been wind tunnel tested to wind speeds of 40 m/s. Windex wind vanes remain the top performing wind indicators in the world and offers exceptional performance with great value. Provides accurate apparent wind direction information for cruisers and racers Saphire jewel suspension bearing makes the device sensitive in light air and responsive in heavy air.