BUILT TO LAST - This high-quality metal tumbler has a powerful motor noise reducing leak-proof barrel and comes backed by a 2-year warranty. PERFECT FOR BEGINNERS Easy to operate! Features an automatic shutoff timer so you can get bigger results and save energy Manufacturered by . EXPLORE CRYSTAL CAVES Geodes are naturally forming volcanic rocks that contain amazing crystal formations. Crack them open and discover beautiful minerals! PREMIUM QUALITY National Geographic selects only the best geodes collected from multiple mines so youre guaranteed to find stunning crystals EVERYTHING YOU NEED Tumbling machine 9 types of rough gemstones (0.5 lb) four polishing grits jewelry fastenings educational guide & instructions INSPIRING A GENERATION Kids love these treasure filled rocks! Promote an appreciation of nature and geology in your child with this fun science kit