KT185 Magnetic Tumbler 185mm Jewelry Polisher Finisher Magnetic polishing machine with Magnetic Cream and Magnetic needle Designed for polishing intricate details, tiny crevices, and multiple settings, but not flat surfaces. This magnetic tumbler can be used to process some rings with stones intact, such as ; cubic zirconia (cz), rubies, sapphires & diamonds. Supplied complete with an acrylic bowl. Magnetic tumbling is an automated polishing process that nearly eliminates the need for cyanide bombing, stripping, and thrumming. 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, and press the "on" button.Tiny steel pins are driven by powerful rotating magnets at the base of the finishing bowl.