The Russians used capsule with a paper with personal information cared inside , I've been told they considered it bad luck so many didn't carry them or left the paper blank .
@CBH: Thats right. But they also used metal dog tags like Germans during the WW2. Check out P.Rios book page 22. The capsule tags were used by officers. Corporals and normal soldiers used metal tags. The most popular form is the one with 8 corners. But the metal tags had different forms, so I dont know, if this is an original RKKA tag oder post war, or used by other East block nations. Regards
Hope it turns out to be real WWII
Your tag is probably the tool, equipment, or other things. More precisely is difficult to say. If you are interested in Russian tags, here on the topics: