Cindy is right on. I purchased a two barrel tumbler for $40 (free
shipping offer, too) from Harbor Freight to bring with me when I
teach workshops. It works like a dream, well....there are so few
moving parts, right! It's sold as a rock tumbler. If you need a
reasonable priced tumbler that will probably stand up to a lot of
use, this is a good bet. It's not as convenient as some to open and
close, but it satisfied my needs for a medium size capacity and
weight that was easy to carry around.