Terahertz is a gemstone originating from Japan that has excellent heat and cold conducting properties and is known to radiate energy/negative ions. This stone is sometimes worn as jewelry to detox and provide relief for aches and pains. We love it because it gets super cold very quickly and is so soothing to irritated skin, helps depuff eyes, detox, and calm. 
 
This Terahertz face roller is great to cool down red or irritated skin, relieve puffiness, help your products sink in, relax and relieve facial tension, and in combination with any of your serums, it can make the skin look plump and juicy!
 
Dipping this tool in ice water is great for puffy eyes and to use as a cold compress on pimples.