This sturdy, economical rotary / rock tumbler from Thumler's Tumblers has a 3 lb. capacity molded rubber barrel with a fifteen-sided interior. The fan cooled motor has overload protection to to prevent overheating. Molded hard rubber barrel is 4” inside diameter x 4” deep. For tumbling jewelry, rocks, sea glass, and other items with wet or dry media. 110 Volt, Made in USA.