Fujiya Adjustable Wrench
Tools are security, and everybody I know and like is drawn to well-made tools that are compact enough to fit anywhere, and could possibly save the day. This isn't your average Crescent wrench. On those, you generally have to go to 16-inches to get one that opens 32mm—enough for the upper bearing cup and locknut on a 1-inch threaded headset. This one does that in 5 1/2 inches, and reduces small enough to squish a mosquito's leg. In-between, it's a 15mm wrench for pedals or track bike wheels, an inconvenient but effective 2mm spoke nipple wrench, and it can stabilize (keep from twisting) a handlebar-end pod while you tighten it in the bar. Fender nuts, rack nuts. You can clamp onto something and bend it. You can use the hole in the end as a cheater bar for a small hex wrench. You can help a sad sack cyclist broken down on the road and riding a bike with all the nuts hex nuts. I'm not even looking at a bike as I type this, and if I were I bet I could find half a dozen more.
This wrench is made in Taiwan to the Japan's JIS standards—the highest in the bicycle industry. If it were made in Japan, it would cost $58, and at that point we wouldn't offer it. If your time were worth the contents of the null set, you could start with a 16 inch adjustable, then go through some hacksaw blades and grinding stones trying to get it down to 5.5 inches and 5.7 ounces—easily packable on any ride. Otherwise, this is a decent deal. In a hundred years it'll still be good and somebody will use it for something good.