These are substantial brass beads made from two caseheads off of 50 cal ammo cases. The caseheads are turned on a lathe to get a nice flat surface, and a 3/8 hole bored through. Then 2 caseheads are sleeved together with a piece of 3/8 od brass tubing, and it all gets silver soldered together. The end result is a very cool, but rather heavy (1.2 oz) bead that can be used for all sorts of things, from a knife bead, oversized zipper pull, or a bead on a piece of jewelry such as a bracelet of necklace.
The beads are made from recycled military brass, so they will have some nicks and dings in them, but it just adds to the character, but don't be expecting flawless, pristine beads made from brand new never fired brass, those would be substantially more expensive.