Consists of a circular black-painted brass sheet cover for 9.75 " dia. liquid compasses. A "V"-shaped aperture can be covered by two swivelling shutters to reduce light from the compass. Cover can be locked against verge ring by means of a milled headed clamp screw. In fitted wooden box 11.5 x 10.75 x 2.2" (29.2 x 27.3 x 5.5cm)