TEKTON Long Arm Ball End Hex Key Wrench Set, Inch,13-Piece | 25262 Heat treated chrome vanadium steel with black-oxide finish Precisely-sized, chamfered ends insert smoothly into fastener head, reducing wear Hinged case opens flat, making it easier to get wrenches in and out Long arm wrenches provide extra reach and greater torque Ball hex ends allow up to a 25-degree entry angle to reach around obstructions