This is the Oceanic SWIV Compass Swivel - Module Features: Proprietary design ensures quick response and smooth movement Top or side reading OceanGlo luminescent floating card Absorbs light and glows Approximately 7 times faster and longer than other materials High visibility lubber line Large ratcheting bezel Direct and reciprocal index points Find your way. For reliable underwater navigation, the SideScan Compass is hard to beat. Large, easy-to-read bearing indicators on our extremely bright OceanGlo luminescent floating card make quick work of navigation, especially in limited visibility.