The clinometer sight was attached to a Vickers .303 machine gun and used for long range fire or a fixed line of fire.
Brass and steel clinometer sight. The top of the sight featured a spirit level. At each end there is a brass and steel winder that can depress or elevate the sight which rides on a semi-circular copper coloured slider. The brass scale on one side is graded in five degree units. A base plate for attaching the item to a machine gun is missing.
Inscriptions & markings
On side one: 'DEP DEGs, ELEV DEGs'
On side two: 'MADE IN AUSTRALIA, F. TOUGH 1942, D(upward arrow)D, A.1553, CLINOMETER SIGHT (MARK IV)'