This GearWrench XL GearBox Double Box End Ratcheting Wrench 12 piece Metric Set is designed with the XL GearBox Design which has a longer beam to increase leverage and torque. The non-ratcheting, standard box end combined with the long pattern length gives this wrench excellent torque capabilities to break a stubborn, rusted fastener. The ratcheting box end then makes the loosening or tightening of the fastener fast and safe. With Unique Technology on Box End it provides off-corner loading for better grip and reduced fastener rounding. The double box end ratcheting wrenches are made from the finest chrome vanadium steel for precision long lasting tool life. Sizes included are 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm and 19mm.