These ratcheting combination wrench sets have an open end and a 12-pt. box end with additional grooves that make it easier to connect with the head of the fastener and connect at more angles for better accessibility compared to a 6-pt. wrench. Combination wrenches have the same metric size on each end for use on one specific size fastener. A gear mechanism on the box end allows the wrench to rotate freely in one direction without removing the wrench head from the fastener and repositioning the tool.