The sextant has a bronze lacquered frame and a wooden handle. The tangent screw, working against a spring load, and the clamping screw are located on the back of the index arm. The sextant has three shades, one orange and two green and four horizon shades, one orange and three green. Index-glass adjustment is made by a screw and on the horizon-glass by a square-headed screw, a detached key and a screw.

Attached to the sextant is a magnifier on a 190mm swivelling arm, which has a frosted glass shade. There is also a threaded telescope bracket in two parts, fitted for correcting collimation error. It has perpendicular adjustment made by a rising-piece and a milled knob. The telescope is 193 mm in length with an inverted image, three cross wires, and a swivelling green shaded eyepiece with a dust cap. An extra drawtube is 80 mm with an inverted image and three cross wires. The sight-tube is 131 mm. Accompanying the instrument is a screwdriver, two adjusting keys, and two rectangular sight-vanes, one with a crosswire the other with a pinhole.

The instrument has a polished limb with an inlaid silver scale from -12° to 150° by 20 arcminutes, measuring to 132°. The sextant has a silver vernier to 20 arcseconds, with zero at the right.

The sextant is contained in a mahogany keystone box.