This unique lighting system makes it as easy to read the wind at night as during the day, from anywhere on the deck. The Windex Light is mounted directly to the masthead fitting of the Windex 10", 15", and under J-Base mounting socket. The non-dazzling light from the 12-volt bulb illuminates the reflecting surfaces of the reference tabs and vane. Completely waterproof with non-corroding, silver parts. Low battery drain: current draw of Windex Light is 120MA.