Features and Benefits * Patented bit holding system forces bit surface to opposing side for maximum bit retention - strength * Packaged in patented impact resistant "slide rail" system * Heat treated socket bases for durability and service ability * Chrome sockets; S2 and alloy steel bits * Includes 6mm, 8mm, 10mm, and 12mm Bit Sockets 4 Piece 3/8" Triple Square Metric Bit Socket Set includes: 6mm, 8mm, 10mm, and 12mm Bit Sockets packaged on a clip rail.