Brand: Blue Marble Product Dimensions (L x W x H): 35.2 x 20.5 x 12.5 cm Item Weight: 2220 grams Sub-brand: National Geographic Make your own gems! – Turn ordinary stones into sparkling gems! This fun kit uses simple operation and a sturdy design to transform rough stones into beautiful gems. A durable tumbler that lasts! – The motor is designed for long life, and the leak-resistant rubber material provides excellent quietness. Perfect for children's STEM learning. A full-fledged polishing kit is included! – Includes a polisher, 4 types of polishing compounds, a sieve, 9 types of real rough stones, and a color guide, making it a perfect gift for boys and girls! Easy operation for fun polishing! – Features a one-touch timer and automatic shut-off function, making it easy to set the number of days. Ideal as a gift for children! AWARD-WINNING PRODUCTS - Blue Marble has a track record of winning the Toy of the Year award and develops products that nurture imagination and creativity. #rocktumbler #rocktumbling #rocktumbler #Christmas present #boys #experiment