To reduce the working swing arc in tight spaces, the open end is angled 15 degrees so the wrench can be flipped over with each rotation to engage the fastener twice as often.

A 12-point box end doubles the available access angles, as compared to a 6-point end. In order to prevent rounding off fasteners, the box end is designed to contact and apply force to the sides of a fastener head and not the corners.

The box end is offset 15 degrees, creating clearance for your fingers and making it easier to reach around obstructions.