TEKTON Folding Hex Key Wrench Set, Inch/Metric/Star, 25-Piece | 25152 Heat treated chrome vanadium steel with black-oxide finish Precisely-sized, chamfered ends insert smoothly into fastener head, reducing wear Contoured shape, with rounded profile and soft, textured grips, comfortably fits your palm and in your pocket High visibility size markings for fast size selection Housings conveniently keep hex keys stored and prevent lost hex keys