The POSITAL IXARC OCD-S6E1B-1416-9A7S-5RW Optical SSI with Preset + Incremental Push Pull encoder provides 16 bit resolution and 14 bit resolution along with excellent dynamic response and is suitable for use in areas with high magnetic fields. A Aluminum flange, Steel housing and void temperature range provide IP66/IP67 environmental protection. Since the rotation of the code discs is an entirely mechanical process, there is no risk of these devices losing track of their absolute position due to a temporary loss of instrument power. No backup batteries are required!