The octant is made from an ebony frame and limb with a black-lacquered brass index arm and fittings. There are decorative inlaid diamond-shaped ivory pieces in both struts, and a decorated inlaid ivory plate on the crossbar. There is no tangent screw and the clamping screw is on the back of the index arm. The octant has two red index shades. Index-glass adjustment is made by a screw and the horizon glass by a lever, wing nut and a milled clamping screw. The sight vane has one pinhole. The octant has no box.

Inlaid ivory scale from -5° to 95° by 30 arcminutes, which is vice versa for the zenith distance, measuring to 95°. The octant has an ivory vernier measuring to 2 arcminutes, with zero at the centre.

The octant is marked on the ivory plate on the crossbar: ‘P. Holm, Amsterdam 1753’. Pieter Holm was a Swedish seaman who ran a nautical school in Amsterdam, where he sold octants that were made by Jacobus Kley of Rotterdam.