Refill your own rock tumbler so you can create beautiful, polished stones! Rock Tumbler Refill Kit contains extra belts to fit the Science Tech Rock Tumbler (sold separately), two 8 oz. bags of gemstone rocks, two bags each of coarse grinding powder, fine grinding powder and polishing powder. Plus, jewelry making accessories: 18" silver tone necklace chain, four adjustable rings, three key chains, three pairs of hanging earring wires, 12 setting holders in three styles, 12 jump ring connectors plus glue. Ages 10+.