The octant consists of a polished brass frame, silvered brass limb, and a brass stop for the index arm. There is no tangent screw and the clamping screw is on the back of the index arm. It has three index shades in pink, red, and green. Index-glass adjustment is made by a screw and both horizon glasses by levers, wing nuts and milled clamping screws. The sight vane has two pinholes and a swivelling shutter and the back sight vane has one pinhole. Floral decoration is found at each end of the limb. The octant has no box.

It has a silver scale from -5° to 95° by 20 arcminutes, which is vice versa for the zenith distance, measuring to 95°. Silver vernier to 1 arcminute, zero at the centre.