The reflecting circle consists of a circular polished brass frame, with a wooden handle. A detached U-shaped bracket holds a second handle with a brass-lined threaded hole for a third handle, which can also be screwed in the front of the frame. The instrument has three rigidly connected index arms on the back of the frame, and a double-ended tangent screw and a clamping screw on the back of one of the arms. It has three index shades, two red and one green, and three horizon shades, two red and one green. Index-glass adjustment is made by a screw and on the horizon glass by a screw and a capstan screw.

Accompanying the circle is a detached magnifier on a 70mm swivelling arm serving all three verniers. 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 collar. The telescope is 185 mm in length with an inverted image and two parallel cross wires. An extra drawtube is 82 mm long with two parallel cross wires. A second telescope is 142 mm long with an inverted image and four cross wires. A third telescope is 75 mm long with an erect image. The sight-tube is 129 mm in length and has two red shaded eyepieces.

The instrument has a polished brass limb with an inlaid gold scale indicated from 160° to 0° to160°, although the entire scale is divided by 20 arcminutes. The reflecting circle has three brass verniers measuring to 20 arcseconds, with the zeros at the left.

The circle is contained in a square fitted brassbound teak box, which is possibly a replacement as teak is unusual for navigational instrument boxes.

The U-shaped bracket was recommended by Mendoza Rios, and according to him first applied by Troughton.