A reader says this is the smallest open-end wrench in the world, with 0.005 in. across the flats on one end and 0.010 in. across the other. The human hair next to the wrench gives a comparative size.

The ratcheting wrench is one of those instruments that sounds frivolous but is actually an invaluable addition to the toolbox. Craig brought 15 years of automotive journalism experience to the Cars ...