The Diamond Pacific MT-4SV Mini-Sonic Vibrating Rock Tumbler is perfect for small, delicate jobs. Thanks to a unique operating system that uses no moving parts, this tumbler is gentle on your materials and lets them keep their original shape even while being polished. An interrupted electronic current creates a gentle vibration that accomplishes the tumbling - no motors, pulleys, or shafts required. Even the hopper itself stays almost motionless; just the contents inside rotate. Operation and intensity are controlled via electronic dials. While the tumbler is running, the load is separated, compacted, and then separated again during each cycle, which improves the process and helps draw fresh abrasive up into your materials each time. As the abrasive begins to break down, it forms a slurry that coats your materials.The Mini-Sonic operates with 3600 vibrations per minute on 60Hz of power and 110 volts. Load capacity is approximately 4 pounds. The hopper is made from cast polyvinyl.Only a small amount of water and abrasive is required for operation. Too much of either will cause material to collect in the hopper and prevent proper rotation.About Diamond Pacific For over 30 years this second-generation family-owned business has manufactured equipment for lapidists - from rock hound hobbyists to professional gem cutters and jewelers. Diamond Pacific hopes to put fun and pride into the craft by manufacturing the necessary tools to ensure superior results. 4-lb. capacity hopper. Cast polyvinyl hopper. Durable ABS plastic housing. 60Hz; 3600 vibrations per minute. Alternating separation/compacting action. Rotation and vibration powered by electric current.