Davis Instruments 10.Sport Wind Vane Windex. The secret is in the sapphire jewel suspension bearing large fin-low inertia van and easy-to-read fully adjustable tacking tab system.Reflector tape on the vane and tacking tabs make WindTrak 10 Sport easy to see day and night. WindTrak vanes are sturdy and when installed properly offer many years of use. They have been wind tunnel tested to wind speeds of 80 knots WindTrak 10 Sport has a 10" (25 cm) vane. Includes glass reinforced polycarbonate J-Base for side top or front of mast mounting on most dinghies smaller boats and sport boats. Stands just 9.25" (23.5 cm) tall and weighs 1.2 ounces (31 g). Specifications for Davis Instruments WindTrak 10 Sport Wind Vane: Manufacturer: Davis Instruments Color: Black Package Contents: Davis Instruments WindTrak 10 Sport Wind Vane Davis Instruments 3120: 10.Sport Wind Vane Windex