Per the Manufacturer:The GearWrench Tools 20-Piece SAE/Metric Stubby Wrench Set includes both 3/8-inch through 15/16-inch and 10mm through 19mm wrenches. The stubby pattern length provides extreme access, while the surface drive plus feature increases fastener grip while preventing fastener rounding. Wrench sizes are indicated by stamps on both sides and the head of the wrench for greater visibility.GearWrench Tools backs its wrenches with a lifetime warranty.