Take your rock tumbling seriously with this top-of-the-line, 1.36 kg capacity professional rock tumbler from National Geographic! This kit has all the features and accessories you'll need to master rock tumbling, start an extraordinary rock collection, and create beautiful jewelry. Contents and Features: Automatic shutoff timer; Reliable, long-lasting motor; Leak-proof tumbler barrel; Noise-reduced operation (75% quieter than plastic barrels); Plenty of stones (1.36 kg) and four levels of grit; 5 Jewellery Fastenings; GemFoam, the most innovative way to add dazzling shine to your polished stones! This high-quality tumbler allows you to set your speed and tumbling time. When the time expires, your tumbler will automatically shut-off, allowing you to choose the perfect amount of tumble time for each grit stage. Plus, our redesigned tumbling barrel dampens sound better than most tumblers out there. The rough rocks provided (1.36 kg) contain nine different gemstones from around the world, and our tumbling grit is labeled by tumbling stage to make the process even easier! Choose your favorite gems and turn them into jewellery with the included necklace, keychain, ring, and two clip-on earring fastenings inside. And don't forget about GemFoam, our exclusive new way to add dazzling shine to your polished rocks! Use GemFoam just like tumbling grit, simply add it to the barrel with your stones and water, then three days later marvel at the shine! GemFoam is reusable too, allowing you to create a truly impressive gemstone collection. National Geographic Toys makes the highest quality hands-on science toys, and all products are backed by exceptional service. About the National Geographic Society: With a mission to inspire people to care about the planet, the National Geographic Society is one of the world's largest nonprofit scientific and educational organizations.