This is a chainmail bag. Typically it's just for gamers to hold their dice. But of course it can have many uses. See it in action on my YouTube link below. And for all you Shapeways designers making your own custom dice, what a better way to protect them, but in a Shapeways printed dice bag!
Check out some really nice dice you can print out as well, if you want something to go into your new bag! http://www.shapeways.com/model/126281/overstuffed_dice_set.html