This 15 Piece 12 Point Full Polish Long Combination Wrench Set by Armstrong produces more torque and while reducing wear and tear providing greater strength and durability. Manufactured to meet applicable aerospace standards: sizes 5/16" through 1". The box ends are offset a true 15° for clearing obstructions and knuckle clearance on flat surfaces while they also incorporate a radius corner design that engages the flats of the fastener, not the corners, providing up to 15%-20% more torque while reducing fastener rounding, enhancing the turning of work fasteners. The shank to box end transition area is also reinforced to provide greater strength. When compared to a hex open end especially, the open end radius design provides greater strength.