Davis Instruments AV Antenna Mount Wind Vane Windex. The secret is in the sapphire jewel suspension bearing large fin-low inertia vane and easy-to-read fully adjustable tacking tab system.WindTrak AV installs onto most whip antennas including Metz and Shakespeare brands with a whip diameter less than 1/8" (3 mm). Combine two installations into one to reduce masthead clutter weight and windage aloft. Rides on low-friction Teflon bearings. Complete with 15" (38 cm) vane reflective tacking arms hardware and instructions for easy installation. Antenna not included. Specifications for Davis Instruments WindTrak AV Antenna Mount Wind Vane: Manufacturer: Davis Instruments Color: Black Package Contents: Davis Instruments WindTrak AV Antenna Mount Wind Vane Davis Instruments 3160: AV Antenna Mount Wind Vane Windex