Chaos, in reply to your questions and comments: A thin pair of polypro socks can be rolled in a small tight package or flat vacuum packed. You put them on under your dress socks, to prevent blisters in a long walk home in dress shoes or loafers; the silcock key will get you into recessed commerical facets with ease. A leatherman may or may not always work. Getting fresh water is a major conern for hydration/ first aid/ and decontamination; A water purifier bottle will filter out chemical contamination. your other preps will not ( consider also putting it in a Ti cup and the whole unit in a light nylon belt bag to get it out of your pack when needed, giving you extra pack room to add scrounged items); The Cop Tool is a purpose designed pry bar/chisel/belt cutter/short serrated blade, much stronger than a LM screwdriver for prying out a train window or opening a train door Its a bit heavy, ~6oz., so its optional; A silcloth ponchco is light and compact and has muliple uses, i.e. poncho, ground cloth, sun shade, wind break. Its much more versatile than a rainshell and; The trauma supplies, especially the izzy bandage are not that big or heavy. you want to be able to put on a bandage/touniquet quickly and with one hand. Just my opinion. YMMV.