These dice are made of metal, which is noticeable by their slightly heavier weight. A special feature is that their sides glow in the dark. Try it: turn off the lights and the dice light up! The Role Playing Game Sets include 7 different dice: D6, D4, 2x D10 (steps of 1 and steps of 10), D8, D20, and D12. They come packaged in sturdy cases with expandable shelves, so you can easily take them with you and play wherever you want. Compatible with Ultimate Guard®: the shelves in which the dice are packaged fit perfectly into the Ultimate Guard® Twin Flip'n'Tray 160.