Nothing(?) to do with sniping or a snipers or a riflemans kit.......... It was a training aid used and still used during map reading and fieldcraft training so that the person being trained to give fire-orders etc etc to the Artillery and mortars. So that the directing staff know that their instructions are fully understood by the trainee instructor who.........
Still in use today especially on the JOTAC courses at Warminster. Used to see them clipped to map-boards every day.
I suppose that anyone COULD use such a beast but by the time you have done the map and compass course you'd be familiar with clock-face target location methods. I say 'anyone' but I don't include types such as REME officers who wouldn't even know how to fold a map!