This is an old model Mini Rayonex. It's the size of a card, so you can carry it in your chest pocket. The Mini Rayonex contains a module (the core component of a dipole antenna structure) that regulates the rhythm of the person who owns it. Carry the Mini Rayonex in your handbag or in a pocket of your clothing. If you are concerned about electromagnetic waves, place it near your body rather than near electrical appliances. I bought it about 10 years ago, but it's in good condition because I've just left it sitting around. I used it by my pillow, and I was able to sleep soundly. Since it's an old model, it doesn't support 5G. It seems to be able to cut off normal electromagnetic waves. There are no instructions. How to use it is as follows: Use it with the text side up. When wearing it, face the text side outwards. When leaving it for a long time, place the W of the text side to the west and the O to the east. Fine waves accumulate in the Rayonex, so if possible, hold the text side up and run it under running water for about 20 seconds every day. (This discharges it like grounding) It is not waterproof, so do not immerse it in water or use detergent. The inside of the Mini Rayonex is like an antenna, so be careful as dropping it or giving it a strong impact may break it. Size: 98 x 57 mm, Thickness: 20 mm Weight: 106 grams