Our 11PC 3/8" Drive Metric Hex Bit Socket Set with FOUR FLAT™ sides is designed from the ground up to be part of the most versatile socket family. Milwaukee® bit sockets feature an innovative design with four parallel flat sides, which deter rolling and are wrench-compatible. This also creates a slim profile to provide the best access in tight spaces. The one-piece socket design offers improved durability compared to two-piece designs by eliminating the risk of the bit separating from the socket base. This set includes a storage rail for better organization. Laser engraved size markings provide easy identification and chrome plating offers rust and corrosion protection. All Milwaukee® bit sockets are backed by a Lifetime Guarantee.