This document describes a hollow rotary gearbox that provides accurate and fast positioning with a backlash of 0.5 arc-minutes and a nominal output torque ranging from 3 to 90 Nm. It has a large hollow rotary table suitable for concise wiring and piping, with features including a maximum backlash of 30 arc-seconds, a hollow bore for wiring or shafts, and smooth and fast positioning and indexing that allows for positional rigidity and handling heavy axial loads. Larger reduction ratios can be achieved by combining it with planetary or right-angle gearheads.