The sextant consists of circular polished brass plates with a lid that when screwed on the back of the instrument serves as the handle. The index arm is moved by a brass stud at the end of the arm, and fitted with a clamping screw and tangent screw, which operate in a slot cut in the upper plate. The sextant has no shades. The index glass is non-adjustable and the horizon glass is moved by square-headed screws with a milled screw shipped in the upper plate. Attached to the sextant is a single lens magnifier on an 89mm swivelling arm attached at the pivot. It has a pinhole sight.

The instrument has an inlaid silver scale from -5° to 160° by 30 arcminutes, measuring to 123° (the digits are read from the pivot). The sextant has a silver vernier measuring to 30 arcseconds, with zero at the left.