Automatic Wire Stripper/Crimper
This product is unavailable
If you don't have one of these in your kit, and are going to tackle wiring, you'll want this guy as your side kick. This has a wire cutter, crimp positions for insulated and uninsulated terminals, and (of course) automatically strips wire from 10-26 Gauge. It pretty much does it all, except wire your bike for you.
Looking for a less expensive option? Try the Automatic Wire Stripper. The crimp positions aren't as great as the one pictured here, but it will work if you already have a set of crimpers in your toolbox.