20 PCS Heated Basalt Rocks Fast Heating Round Massage Stones with Bamboo Box Electric Spa Hot Stones 220V EU Plug Item Type: 20 PCS Stones Massage Set Material: Basalt, Logs Quantity of Products: 4 x Massage Stones (Approx. 8 x 8cm / 3.1 x 3.1in), 4 x Massage Stones (Approx. 8 x 6cm / 3.1 x 2.4in), 8 x Massage Stone (Approx. 3 x 4cm / 1.2 x 1.6in), 4 x Massage Stones (Approx. 6 x 5cm / 2.4 x 2in) Features: not waxing, not oiling, original ecology Suitable: 1. People of long term facing computer, TV, often play mahjong, often drive cars 2. People of shoulder, neck and back easier get pain, mental tension and stressful 3. People of long term insomnia, neurasthenia, headaches, dizziness, hair loss, memory loss 4. People of insufficient blood supply to the brain, lack of oxygen, shoulder and neck strain, hyperplasia 5. People of long term constipation, belly drainage, gastrointestinal discomfort 6. People of blood disorders, menstrual disorders, dysmenorrhea, etc.