The Berry's tumbler design is the pinnacle of achievement in vibratory tumblers: It produces the most robust vibratory vortex tumbling action, holds plenty of capacity, and costs little enough for everyone to afford. Here's how it works: You fill the bowl with corncob grit and a little brass polish (order separately) and then drop in the cartridge brass you want to clean. Turn on the switch and watch the rolling, vibrating, tumbling action! Your brass gets cleaned and polished with ease and the hand loads you make from them fit, feed, and fire reliably.Bowl Shape and Motor - The Model 400 bowl has a thick, rich wall material that's molded into a smooth, rib-less, ovoid shape. This shape produces the smoothest and fastest vortex tumbling action. The motor is equally tough and reliable... And it's got a THREE YEAR WARRANTY to back it up.Huge Tumbling Capacity - The Berry's Model 400 tumbles up to 1,000 pieces of 9mm brass, 600 of 45 ACP, 450 of .223 Remington, and 250 of 30-06.For more information on tumblers, see our Berry's Tumbler Page.