Lev-o-gage mounts easily on bulkhead (no hardware required), to monitor heel angle. Aids in trimming sails for optimal speed. Made in USA. Tube assembly made of special shatterproof copolymer. Monitors tilt angle from -45 to 45 degrees. Brass indicator ball rides in special damping fluid. Numerals/hashmarks are engraved and hand painted for long life and great visibility. Saturn yellow tube assembly for easy reading. Mounts with high-bond tape. Its convenient size will allow for mounting on almost any surface. No hardware required.