Perfect angular range for modern performance cruisers, sailboats and sport boats. Higher resolution from 15 degrees to 15 degrees. Monitors heel angle from 30 to 30 degrees. Assembled in USA of mostly USA parts. Numerals and hashmarks are engraved and hand painted for high contrast and easy visibility. Saturn yellow tube assembly is shatterproof. Brass indicator ball rides in special damping fluid. High bond foam tape makes attaching to bulkhead easy. Great aid for finding and holding optimal heel angle.