Davis WindTrak 15 Wind Vane Bundle with J-Base Mount (2 items) - The 15" Wind Vane has a sapphire jewel suspension bearing, a large fin, low-inertia vane, and easy-to-read, fully adjustable tacking tab system. Great for boats +15 feet. Reflector tape makes it easy to see day or night. Stands 12.75" tall and weighs 3.6 ounces. The J-base Mount extends your vane away from obstructions. Mount on the back of the mast for easier viewing from the cockpit. 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!