The Windex 10 is the standard model wind vane for ocean racing and cruising. Windex 10 Features: Length 10 inches Sapphire jewel suspension. Reflective markers on vane and tacking tabs for high night visibility. Can be fitted with Windex light. Weight 38g. WINDEX is the standard wind indicator/burgee around the world. Windex have a light, balanced vane with large fin area and lowfriction SAPPHIRE jewel suspension. These features make the Windex respond quickly and accurately at wind speeds as low as 0.2 knots (0.1metre/second). The tacking tabs can be adjusted to the apparent wind direction for port and starboard tacking. The Windex vane and tacking tabs feature reflective markers under the vane making them highly visible at night. For night sailing we recommend the addition of the Windex light