Avoid veering...and collisions! Awareness of the rudder angle is the most important safety factor. This is especially true while moving in and out of your berth, drawing alongside another boat, picking up a skier, mooring, or any other "close call" situation. Davis rudder position indicator gives instant visual reference of rudder angle. The pointer swings a full 30 deg. with each revolution of the wheel. Mounts easily with it`s self-adhesive pad directly to your hub. Approximately 2" in diameter. Rugged, hermetically sealed, weatherproof and sunproof housing ensures long life. No cables, adjustments, or electricity required; gravity power makes it simple and service-free. Suitable bor boats with mechanical and single station hydrolic steering systems.