The smallest of PRTs with external gear for direct drive via toothed belt is now available for the toothed belt profile HTD5M. Similar to the normal case of externally toothed slewing ring bearing, the inner ring is fixed and the outer ring driven. Simultaneously, specially widened outer ring carries the gear that is to be moved. The light weight, rugged design ready to install device is lubricant- and maintenance-free. They find application in automation, fixtures, precision engineering