The Windex XL is a high-performance wind direction indicator for larger ocean racing and cruising yachts. Rugged and wind tunnel tested to 80 knots, it features Windex’s proven design concept with a sapphire bearing for extreme sensitivity and endurance.SpecificationsVane length: 570 mm (23)Height: 570 mm (23)Weight: 150 gr (5,4 ounces)It has a 5/16 thread, or you can drill an 8 mm hole and mount it with a washer and a nut