This is a necklace featuring a terahertz magnet and natural tourmaline. The terahertz magnet is said to be effective for headaches and stiff shoulders. As shown in the fourth photo, the magnets stick together due to their magnetic force. The clasp is made of 18-karat gold (stamped 750). I purchased this about two years ago and have kept it at home without using it. I threw away the original box soon after purchasing it and have been storing it in a different necklace box (the box has some stains: see the fourth photo). If you would like the box, it will be this one. * If you do not want the box, I will deduct 100 yen, so please let me know in advance.