This tumbler comes with 3 – 1.5lb rubber barrels. The rubber barrels are quiet and long wearing. The 1.5 capacity barrels are sized for smaller stones up to 1 inch. This tumbler is particularly handy for those wanting to do smaller batches of stones. The barrels are molded with special ribs to increase the tumbling action. The Base of this tumbler is also a 33B base so the 3 barrels can be replaced with 2 – 3lb barrels at will. Base dimensions 6.25″W x 10.25″L.