Their claim is maximum strength with minimum material. Less weight, less fatigue for the mechanic, easier to get into tough-to-reach area. Their Flank technology prevents rounding off nuts & bolts since the torque is spread on the flat edges of the nuts & bolts, not the corners. FLank Plus open-end wrenches have jagged teeth to give additional bite when torque the nuts & bolts. Though Snap-On typically cost 4 times more than Craftsman or Husky, it's worth every penny.
