This set includes a heater bag and stones, allowing you to easily experience hot stone therapy at home. Heater Bag Set Width 17cm x Height 22cm (internal heater bag) Stones (Basalt) 3 pieces Breakdown: (4.7cm x 6.7cm) 1 piece (5cm x 6cm) 1 piece (6cm x 6cm) 1 piece Place the stones in the heater bag and plug it into an outlet. The stones inside the heater bag will accumulate heat. You can use the stones alone or in combination with oil massage for effective results. The stones (basalt) are made from volcanic lava. They excel at retaining heat and are recognized for numerous effects, including far-infrared effects, healing effects, and the natural geothermal energy effect. Therefore, they have been treasured as mystical stones by Native Americans and passed down to the present day. Health Natural Healing Natural