Armstrong 52-677 12 Point Metric Satin Finish Long Combination Wrench Set, 10-Piece Box Ends Incorporate a Radius Corner Design That Engages the Flats of the Fastener, Not the Corners, Providing Up to 15% -20% More Torque Box Ends Are Offset a True 15Degree for Clearing Obstructions and Knuckle Clearance on Flat Surfaces The Shank to Box End Transition Area is Also Reinforced to Provide Greater Strength Open End Has a Radius Design for Greater Strength; Especially When Compared to a Hex Open End Large Size Stamp on Both Ends of the Wrench and Both Sides of the Wrench for Ease in Identification