the unit itself is good it heats and works well [SEP] so to start the unit itself is good it heats and works well the stones on the other hand are crap they heat up quick and quick to cool and get way too hot without retaining any heat not for professional they are like garden stones you can find anywhere wish it would give you nice stones for the price going to have to buy a set of basalt stones that will fit this so that i can have a professional set for hot stone massage