Magnetic Tumbling is an automated polishing process that nearly eliminates the need for cyanide bombing, stripping, and thrumming. Tiny steel pins are driven at high speed by powerful rotating magnets at the base of the finishing bowl. Most finishing operations are completed in under 30 minutes. Just place your jewelry pieces, the steel pins, water, and special burnishing compound in the bowl, set the timer, and press the "ON" button. Shuts off automatically. Designed for polishing intricate details, tiny crevices, and multiple settings, but not flat surfaces. Choose the right size magnetic tumbler from four different sizes to suit your finishing needs. As a detergent, we recommend our no. 910 Tumbling Soap Powder.