This tumbler provides a smooth, polished finish to rocks, semi-precious stones, glass, and even metals! Tumbler runs quietly at a low speed due to its rubber tumbler barrel. The cutting edge design allows it to run for days at a time to ensure a smooth finish! This small double barrel tumbler has two 3 lb. barrels; each with a quick-seal closure. Tumble twice as much at one time, or run two operations at once such as polishing and grinding. Simple to operate and UL approved. Capacity: 2 x 3 lbs, or 6 lbs of total material.