Learning And Exploring Through Rock Tumbler Rock Tumbler for Kids / Rock Tumbler for Adults Make rock collecting more fun and educational while boosting imagination and hands-on skills. 3LB Large Leak-proof Rubber Barrel With 3LB extra large barrel, that means you can polish more rocks at once than 1 lb or 2.5 lbs drum. To prevent the liquid from leaking during polishing, our rock tumbler is designed with double stainless steel top cover. Discover the beauty of polished stones ! Explanation: The motion in the barrel of the polisher simulates the natural action of flowing water or ocean waves. Beaches and riverbeds contain rocks and pebbles smoothed by water and the abrasive sand it carries. As rocks grind upon one another with constant water or sand in the mix, they begin to round and smooth. Although this is a constant process, it does not however, naturally polish the rocks. The complete process usually takes 4-6 weeks. Specifications Barrel Capacity: 3LBEasy-to-follow rock tumbling instructionsNoise reducing leak-proof barrel with aluminum lidSimple instructions and settings make rock tumbling fun and easy100% natural ground walnut shells provides excellent heat conductingTiming belts has greater flexibility and abrasion resistance than normal belt