Your junior scientist will love this Rock Tumbler Kit from Elenco. Your child can create beautiful polished stones and make jewelry keepsakes for friends, family or for their own. The set includes the rock tumbler, an AC/DC transformer, rocks and 4 grinding grits. Jewelry-making components include: an 18" necklace chain, 4 adjustable rings, 3 key chains, 3 pairs of hanging earring wires, 12 setting holders in 3 styles, 12 jump ring connectors, glue and easy-to-read instructions.