IDEAL TILT READING - Monitors tilt from -30 to 30 degrees. Brass ball rides in special damping fluid for smooth, accurate readings. EASY TO READ DISPLAY - Brass ball instead of bubble included in bright Saturn yellow tube assembly. Engraved and hand painted numbers make for a functional, easy-to-read display. SHATTERPROOF DESIGN - Tube assembly is made out of a rugged copolymer "flex tube" for ultimate durability. MOUNTS WITH 3M VHB TAPE - Lev-o-gage includes a piece of 3M VHB (Very-High Bond) tape on the back for easy mounting. MADE IN USA - From durable, high-quality materials. 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.