* 4 1/2" PowerDamp Plus, High-Visibility Blue Dial with Extra Large White Numerals * Easily Installed, Fits 4.75" (12.07 cm) Mounting Hole. * Built-in Compensators to Easily Adjust for Deviation * Scientifically Matched Sapphire Jewel & Hardened Steel Pivot Dial Movement * Internal Gimbal Systems for Maximum Stability During Adverse Pitch and Roll Conditions * Powerful DirectiveForce Magnets for Fast Heading Lock-on * Exclusive Built-in Green NiteVu Night Illumination in Movable Sun Shields * 45 Degree Lubber Lines * High Temperature Construction for Extended Operating Range * Custom Fitted Protective Covers Available * 100% Repairable * Exclusive 5-Year Ritchie Warranty