The Milwaukee 12pc 3/8 in. Drive 12-Point Metric Deep Well Socket Set with FOUR FLAT sides is 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 laser-engraved size markings provide easy identification, and chrome plating offers rust and corrosion protection. This set includes a storage rail for better organization. All Milwaukee sockets are backed by a Lifetime Guarantee.