Terahertz Ring - 1 piece Please choose one from ① to ⑥. ① Size 29 (Ring inner diameter 22.4mm) ② Size 26 (Ring inner diameter 21.3mm) ③ Size 23 (Ring inner diameter 20.3mm) ④ Sold Out ⑤ Size 13 (Ring inner diameter 17.2mm) ⑥ Size 13 (Ring inner diameter 17mm) If you would like to purchase multiple pieces, please let us know before purchasing. We will create a dedicated page for you. 【Terahertz】 Terahertz stone is a mineral artificially created by melting quartz at high temperatures and collecting silicon. The 1 trillion vibrations per second (terahertz waves) emitted by terahertz stone penetrate various substances such as wood and plastic. Also, because of its high thermal conductivity, when applied to ice, the vibrations plus the heat conduction from the hand will quickly melt the ice. It is said to have effects on promoting blood flow and enhancing natural healing ability, and is widely used in medical and industrial fields. Not only is it attracting attention for its positive effects on beauty and health, such as cell activation, improved blood flow, and skin firmness, It is also popular as a "scientifically effective power stone."