11 mm, Box End Wrench, Metric, Insulated Finish, Number of Points: 12

Box-end wrenches have an enclosed head on one end of the handle and provide a more secure grip on the full length of the handle compared to a double end box wrench. These single-end wrenches are metric size for use on one specific size fastener. The enclosed head has more contact to the fastener and allows more torque than an open-end wrench since the box end is less likely to slip off the fastener.