Although when sold in shops, or found amongst the rubble, these items appear to be bracelets shaped in the form of a spider, in acuality they are real living spiders. These spiders have evolved a highly specialised form of life. If one is placed over the wrist, then the spider will waken, and sink it's fangs into the wrist, thus starting it's symbiotic relationship with it's host (the spiders can easily be removed if so desired). The origins of these spiders is a mystery, though most sages believe that it is some as yet undocumented demi-plane.