Patented bit holding system forces bit surface to opposing side for maximum bit retention - strengthPackaged in patented impact resistant "slide rail" system Heat treated socket bases for durability and service abilityChrome sockets; S2 and alloy steel bitsIncludes 1/8", 5/32", 3/16", 7/32", 1/4", 5/16", and 3/8" Bit Sockets7 Piece 3/8" Drive SAE Long Ball Hex Bit Socket Set includes: 1/8", 5/32", 3/16", 7/32", 1/4", 5/16", and 3/8" Bit Sockets packaged on a clip rail.