Consists of a brass bearing plate, graduated to 360 degs, quadrantally in degrees and to 1/4 points. A course setting pointer is mounted at centre of plate, turned by a knurled knob. Mounted on a frame which is fitted with two folding sight vanes, one of which carries a slit with a sliding frame fitted with a coloured filter. The other is a frame with a sight wire and black glass reflector. Carrried on a black-painted brass tripod 16" (40.6cm) long, made to clip onto the top of a binnacle. In fitted leather travelling case 22 x 9 x 5 " (56 x 22.9 12.7cm).