A trail running pack or enhancement for your halloween cross dressing ;)
For those confused by the lack of info: don't forget the U.S. regulatory hurdles that must be crossed w/ the coast guard, etc. to get approval on PFD's. There'd be no profit left in the item once all was said and done(unless mass appeal was guaranteed of course). Not to mention, some nimrod who decides to float some class IV and forgets to inflate his Platy. Once the EMT's pull his blue corpse from the river, surviving family members may decide to take a piece of MLD for themselves. No more UL gear for us folks. End of story.
Might make a nice fishing vest too.