Why? Because the $25 piece of metal is eight different sizes in one, starting at 1/4 all the way up to 3/4 inch. Plus both ends are compatible with a bunch of different styles of fasteners. So on a day when you're doing some work around the house, whether you're fixing the sink or doing maintenance on your bike, you won't be wasting time rummaging around for wrench after wrench. More here.