Designed for beachgoers, ocean athletes, and marine professionals, Sharkbanz use patented magnetic technology developed by marine biologists to deter predatory shark species and can also be used to deter stingrays for additional ocean safety. Sharkbanz products are the embodiment of almost two decades worth of peer-reviewed scientific research, including independent government testing on the use of magnetic technology as an active and effective shark deterrent. Used but still in perfect working order. Some scuffing as seen in photos. The magnet in the wristband is undamaged.