Size: 13.5 (thick) Terahertz ore is a silvery power stone similar to Gibeon and hematite, and it is said to emit a frequency that vibrates approximately 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 3 μm to 1000 μm, possessing the properties of both light and radio waves. It is attracting attention as a stone that promotes beauty and health by promoting blood flow and relieving stiffness due to its vibrations. 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. Please choose a size that is loose enough that it won't fall off. That's better for blood circulation. Combined discounts are ¥200 off per item from the second item purchased. 2 items purchased: ¥200 off 3 items purchased: ¥400 off 4 items purchased: ¥600 off Thank you!