TEKTON Jumbo Hex Key Wrench Set, Inch, 3/8-Inch - 3/4-Inch, 6-Piece | 2535 Chrome vanadium steel wrenches are heat treated and black-oxide finished Precisely-sized, chamfered ends insert smoothly into fastener head, reducing wear Long arm wrenches provide extra reach and greater torque Snap-in carry case holds wrenches securely Easy-to-read sizes marked on case for fast wrench selection