The PPCo scope was the most common of the various scopes used by British forces during WWI. Of the 13,150 scopes of all types ordered by the War Office, 4,072 were PPCo scopes produced by the Periscopic Prism Company of London (Pegler, 2022).
The PPCo was a 2x scope measuring 12.25in long and weighing around 18oz. Elevation was controlled by a top mounted turret marked from 100yd out to 800yd. Windage was adjusted by using two small metal screws on the sides of the scope body. The reticle was a post and crosshair. The scope was normally fitted with a dovetail mount, although some examples used other mounts not produced by PPCo.
The PPCo was possibly developed as a modified copy of the German Fuess Helios 3 scope.
.....
Video by Forgotten Weapons
Pegler, M. (2022). Sniping rifles in World War I. Bloomsbury Publishing.