B-81-WM Compass Features:- 3inch (72 mm) CombiDamp Dial- Adjustable and Removable with Bracket and Thumbscrews- Exclusive Built-in Green NiteVu Night Illumination- Scientifically Matched Sapphire Jewel and Hardened Steel Pivot Dial Movement- Powerful DirectiveForce Magnets for Fast Heading Lock-on- Movable Sun Shield- High Temperature Composite Construction for Extended Operating Range- Custom Fitted Protective Covers Available- 100% Repairable- Exclusive 5-Year Ritchie Warranty