Large 6.5” clinometer for sailboats. Ideal for your your sailboat, pontoon boat, or other marine vehicle. Monitors heel angle from -50 to 50 degrees. Brass indicator ball rides in special damping fluid. Mounts to your bulkhead and aids in trimming sails for optimal speed. Large size and engraved/hand painted numbers make for a functional, easy-to-read display. One of the must-have accessories for boating or sailing.