8-piece Flex-Head Ratcheting Combination Wrench Set, Metric 9-17 mm, 72-Teeth, Cr-V Constructed, Nickel Plating with Organization BagOur wrenches are made from high quality heat treated Cr V alloy and Nickel plated for durability. The box end head is precision machined to fit tightly onto fasteners. It can also be pivoted 180 degrees to access tight spaces. The 72 teeth ratchet gear inside the box end requires a 5 degree working swing arc only, enabling an easy and fast operation. This wrench set includes 8 piece wrenches covering sizes 9,10,11,12,13,14,15,17mm, satisfying most of