Oh Gee, My Purification tablets are running out, and my matches are all gone. By the light of my Photon 2 (in the wrong color for night vision ) I see 72 hours have come and gone and something is MOVING in those funny looking bushes. I guess I better give up and die now. The PSK is to provide what cannot be EASILY improvised and fabricate what CAN. Yes, you better have a knife and more important the mindset and training to think " outside the box" especially the one that says Altoid.