Covington's Rolling Tumblers are stout American-made machines built to last. Units are powder coated for durability and longevity. Solid plastisol barrels have raised ridges inside to aid in the tumbling process. Two, steel support shafts are cushioned by nylon sleeve bearings. The barrel rests on the steel supports and lifts off for easy inspection and cleaning. Our new barrels are made of softer black plastic to help with noise. These barrels have been shown to have a longer life expectancy, and Covington provides a 1 year warranty on the barrel too!