WindTrak AV Antenna Mount - Extra Wind Vane Only WindTrak wind vanes continue to offer 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. 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. 15" (38 cm) vane. Antenna not included.