One of these just came over the transom. It's an interesting invention for those who live in or visit cities that essentially forbid you to carry anything like a weapon (Boston, as I recall, forbids even pepper spray, unless you have a carry permit). It's a lanyard for your key ring that, if you have a heavy enough ring, coincidentally turns it into a weapon. Just coincidence, understand. Just like the auto theft device known as "The Club" just coincidentally makes a good club. A .45 would beat either, but in some high-crime jurisdictions that's not an option, a legal option anyway.