New, Unused Gua sha tools are made from various materials, and the one said to be most effective is ★Terahertz ore! The terahertz waves emitted by terahertz ore are high-frequency waves that vibrate 1 trillion times per second. Terahertz waves have high thermal conductivity, so they have the power to melt ice. It doesn't rust, so it's easy to clean with water! Size: 11.1 x 4.5 cm, Thickness: 8.1 mm Weight: 60g 《How to Use》 1. Run it over your hair as if combing it. 2. Gently massage from the hairline to the crown of the head. 3. Gently massage from the crown of the head to the neck. 5. Gently massage from behind the ears to the crown of the head. 6. Focus on pressing and massaging behind the ears. The head is the only part of the body that you can do every day, so use it as you like. Recommended timing is after bathing, and it's also okay to use it while watching TV. The key is to apply pressure with the weight of the gua sha tool without rubbing it too hard! Comb type Comb