This unique lighting system makes it as easy to "read the wind" at night as during the day, from anywhere on deck. The Windex Light is mounted directly to the masthead fitting of the Windex 10 and 15. The non-dazzling light from the 12-volt LED bulb illuminates the reflecting surfaces of the reference tabs and vanes. Completely waterproof with non-corroding, silver parts. Low battery drain: current draw of Windex Light is less than 100mA.