A British World War 1 Brass Telescope Gunsight used in all marks of the Male Tanks. Measuring some 770 mm to 783mm when screwed out for focusing it carries the markings TS No.15 Mk1 No. 96491, K & J Beck London.
A x2 magnification it is in overall very good condition with fungus or dirt on the objective and oculars lenses. Since these have no prisms cleaning should be a simply exercise, both lenses appearing to be held in by external screws.
A crosshairs reticule remains in the ocular lens.
The last image shows one of these sights next to a 6 pound artillery piece in a Male tank