None. I view Doug's kit as an extension to the stuff I was already carrying. (I guess you could look at it either way...)

I already carry a whistle, two lights, a knife, lighter, etc. In my backback are various meds for allergies, etc (Benadryl and Advil, mostly).

If (when?) I buy another one, though, it'll be different. The others kits will go in various bags in various places and will need additional stuff.

The nicest thing about the kit, from my point of view, is that a single source provides so many useful items. I've yet to find one web site that sells all the stuff I want, so shipping costs really increase total PSK cost.