2 3/4 Easy to Read Direct Reading Dial. Easily Installed, Fits 3. 75 (9. 53 cm) Mounting Hole. Internal Green Night Illumination. Built-in Compensators to Easily Adjust for Deviation. Scientifically Matched Sapphire Jewel & Hardened Steel Pivot Dial Movement. Powerful DirectiveForce Magnets for Fast Heading Lock-on. Movable Sun Shield. High Temperature Composite Construction for Extended Operating Range. 100% Repairable. Exclusive 5-Year Ritchie Warranty.