Subject matter of stone : Calcium Carbonate. https://www.amazon.com/dp/B07816Y7XX
Comes Complete with 6 Large(2.75″x0.71″) & 6 Small(1.8″x0.71″) Hot Stones
Lightweight (4.4 pounds w/stones) and Portable, Plus No Water Wanted
Dual Heating Elements Heats Stones to 122° F in about 10 minutes, at the same time as outer case is still cool
Color:Blue. An excellent addition in your observe at an reasonably priced value!
Replacement stones to be had at: https://www.amazon.com/dp/B07816Y7XX