Our 3/8" Drive 18MM 6-Point Socket with FOUR FLAT™ Sides was designed from the ground up to be part of the most versatile socket family. MILWAUKEE® sockets feature an innovative design with four parallel flat sides, which deter rolling and are wrench-compatible. The socket sizes are stamped into the flats providing you with improved, easy-to-read visibility. These deep and standard socket sizes have optimized geometry to reduce bolt rounding and stripping. We back all our sockets with a lifetime guarantee.