Course Minder Movable Bezel with Heading Memory Indicator Remembers the Way... so you don't have to 2 3/4" Direct-Reading Dial Low Mounted Height Surface Mount Easily Installed. Extended Temperature Operating Range with Composite Construction & Diaphragm Exclusive Directive Force Magnets Hardened Steel Pivot and Sapphire Jewel Movement No Wiring or Power Needed Twist On/Off for Easy Removal for Security, Transport & Storage