Smitty.
A few years back a friend gave me an off the shelf PSK as a gift. The contents of the kit were pure crap, all but this thing. It is a spear head designed to be carried in a PSK. The holes are to fix it to a stick with nails and the back is a can opener/screwdriver. I fixed it to a broom handle last year and spent hours at the beach (in BC) in waist deep water spearing crabs and stuff. It worked so well that it has found a permanent home in my PSK. I have a friend (who is a metal worker) to make me more of them.