The quintant has a varnished brass diamond-pattern frame with a wooden handle. The tangent screw and clamping screw are located on the back of the index arm. The instrument has four green shades and three green horizon shades. Index-glass adjustment is made by a screw and on the horizon glass by capstan screws, a square-headed screw and a detached key.

Attached to the quintant is 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. There is also a magnifier on an 83mm swivelling arm. The telescope is 187 mm in length with an inverted image and two parallel cross-wires. An extra drawtube is 79 mm long with an inverted image and four cross wires. A second telescope is 82 mm long with an erect image. Accompanying the quintant is a sight-tube which is 81 mm in length, two green shaded eyepieces, an adjusting pin, a milled adjusting key, and a magnifying glass marked ‘E M’.

The instrument has a polished brass limb with an inlaid silver scale from -5° to 165° by 10 arcminutes, measuring to 145°. The quintant has a silver vernier measuring to 10 arcseconds, with zero at the right.

The quintant is contained in a mahogany keystone box, with a trade label in the lid for J. B. Potter, successor to R. B. Bate, and a card of Staff Commander Edward Mourilyan RN marked in handwriting, ‘A Remembrance from the [Mourilyan] family to Edgar Tarry Adams’.