The Milwaukee Shockwave Impact Duty 3/8 in Drive 5/16 in Standard 6-Point Socket features the boldest, longest-lasting markings and extreme impact durability in high torque applications. The stamped and ink-filled size marking enables an accurate socket selection every time throughout the life of the socket. Engineered with high-strength forged steel for optimized performance in heavy-duty applications and a non-slip hex geometry prevents fastener rounding. The dual-hole design and ring groove allow for easy socket attachment and removal. All Shockwave Impact Duty Sockets are backed by a Lifetime Guarantee and meet ASME industry standards.