Size: Width 29.9mm Inner circumference 23.0cm Terahertz ore is a silvery power stone similar to Gibeon and hematite, and it is said to be a stone that emits a frequency that vibrates about one trillion times per second. Terahertz waves are a type of electromagnetic wave, emitting a long frequency, between 1 trillion Hz and 100 trillion Hz, with a wavelength of 3μm to 1000μm, and have the properties of both light and radio waves. Its vibration is attracting attention as a stone that promotes beauty and health by promoting blood flow and relieving stiffness. According to NASA, these terahertz waves are "transmission wavelengths" that penetrate matter and reach human cells, thus having an activating effect, and are currently being researched worldwide. This is an extra-large size. We offer a discount of 200 yen for each item from the second item purchased. 2 items purchased: 200 yen discount 3 items purchased: 400 yen discount 4 items purchased: 600 yen discount Thank you! ❣️