Size: Width 14.0-14.1mm Inner circumference: 17.0cm Terahertz stone is a silver-colored power stone similar to Gibeon and Hematite, said to emit a frequency that vibrates approximately one trillion times per second. Terahertz waves are a type of electromagnetic wave that emits long frequencies, between 1 trillion Hz and 100 trillion Hz, with wavelengths between 3μm and 1000μm, possessing properties of both light and radio waves. Its vibrations are noted for promoting blood flow, relieving stiffness, and enhancing beauty and health. According to NASA, these terahertz waves are "penetrating wavelengths" that can reach human cells, promoting activation, and are currently being researched worldwide. Combined shipping discount is 200 yen off per item starting from the second item. 2 items purchased: 200 yen discount 3 items purchased: 400 yen discount 4 items purchased: 600 yen discount Thank you! 1100