The quintant has a bronzed brass frame, with a wooden handle. The tangent screw and clamping screw are positioned on the back of the index arm. The instrument has four grey shades and three grey horizon shades. Index-glass adjustment is made by a screw and on the horizon glass by capstan screws.

Attached to the quintant is a magnifier on a 60mm swivelling arm. 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 188 mm in length with an inverted image and two parallel cross wires. A second telescope is 76 mm long with an erect image. An extra drawtube is 64 mm long with two parallel cross wires. The sight-tube is 94 mm in length with a red shaded eyepiece and an adjusting pin.

The instrument has a polished brass limb with an inlaid silver scale from -5° to 160° by 10 arcminutes, measuring to 140°. The quintant has a silver vernier measuring to 10 arcseconds, with zero at the right.

The quintant is contained in a square mahogany box, with a trade label in the lid for Henry Hughes and Son, 59 Fenchurch Street, London. Marked on the lid is the inscription, ‘D42’.

‘D42’ was the Hydrographic Office serial numbering adopted in February 1828, whereby D was the letter given to sextants.