The sextant has an anodized brass triangle-pattern frame and a wooden handle. The tangent screw (the thread has a protective brass cover) and clamping screw are on the back of the index arm. The instrument has four shades, three red and one green, and three horizon shades, two red and one green. Index-glass adjustment is made by a screw and on the horizon-glass by capstan screws.

Attached to the sextant is a magnifier on an 80mm swivelling arm with 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 180 mm in length with an inverted image and four cross wires. An extra drawtube is 77 mm long with an inverted image and two parallel cross wires. A second telescope is 89 mm long with an erect image. A third telescope is 68 mm long with an erect image (star finder). The sight-tube is 82 mm in length with a red shaded eyepiece, an adjusting pin, and a magnifying glass. It is marked on a brass plate, which is now detached, ‘Special prize presented to J.B. Hewson for executive ability & all-round efficiency’.

The instrument has a polished brass limb with inlaid silver scale from -5° to 150° by 10 arcminutes, measuring to 129°. The sextant has a silver vernier reading to 10 arcseconds, with zero at the right.

The sextant is contained in a square fitted wooden box.