The octant has a black-lacquered brass strait-bar pattern frame and a black plastic handle. The white plastic micrometer drum and pressure clamp are located at the bottom of the index arm. The octant has four green shades and three green horizon shades. Index-glass adjustment is made by a screw and on the horizon glass by a screw and a capstan screw. Attached to the octant is a threaded telescope bracket without adjustment. The telescope is 38 mm in length with an erect image. Two unidentified parts are missing. The octant is contained in a square fitted Bakelite box, with a Huson, H. Hughes and Son Ltd certificate of examination in the lid, dated 17 January 1945.

The instrument has a polished brass limb with an inlaid silver scale from -5° to 120° by 1°, measuring to 95°. Micrometer to 1 arcminute.