PFD? Lightweight for packing in?

I am looking online at PFD’s and not finding much info on how much they weigh…just floatation, etc. So does anybody out there have a rec on whitewater rated pfd’s that are lightweight?

The astral nova is pretty light, relatively inexpensive, has a thin back (doesn’t interfere as much with the seat), and is readily available from REI, Backcountry.com, etc…