Review (3/5): Not the greatest!
I like this clamshell but there are better options out there. I give a lot of hot rock massages. Start with some oil to loosen up the body, then use the hot rocks, then massage again after. My last set looked almost like a crock pot. You filled it with water, put the rocks in (of which, there were many different shapes and sizes), let them get to a temperature that the person being massaged liked, and you took them out and put them on their body. The problem here is, there's no water. There's no set temperature. It only gets so hot and all of the rocks are round and grainy. Even the largest rocks are not that big and I find that they don't sit well on a person's body. If you're just buying this for fun, than, by all means, give it a go. If you're doing this professionally, for money, or because you are interested in hot rock massage, there are other types available that will better suit you and your "client".