This is one of the best rock tumblers for polishing rocks that there are out there. This one is very durable and it is very easy to use. All that you need to do is to plug it in then it is good to go. This one is actually very nice and it looks very professional. When you buy it, it comes with some polishing grit and some instructions.
I personally bought this rock tumbler so that i could powderize aluminum foil in order to make my own aluminum powder for coloring paint. It worked great and i had no problems doing this. (I had to buy extra ballbearings)
This rock tumbler does the job. It is able to be left on for days on end and it is also able to stay on that long without heating up very much.
I highly recommend this rock tumbler to anyone who is in need of polishing rocks or grinding certain materials.