METRIC ALLEN SOCKET SET: Each allen socket is 3” in length with a 3/8” drive metric allen hex driver in a one-piece construction for loosening and tightening tough bolts and nuts. IMPACT ALLEN SOCKETS: This allen socket set is made of heavy-duty and dropped-forged chrome molybdenum (Cr-Mo) steel for maximum torque strength and durability with a black phosphate coating for long-life. LONG-REACH LENGTH: These hex bit sockets are perfect for mechanics and electricians as the three-inch long length reaches places regular size impact sockets will not. HEX SOCKET SIZES INCLUDE: A full spectrum of hex driver sockets (Metric) including 4, 5, 6, 7, 8, 10, and 12-millimeter hex sizes. LASER-ETCHED SIZE MARKINGS: The laser etched markings are engraved on each individual impact hex socket for easy identification and stores in a heavy-duty blow mold case for organization and convenience.