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 1/16" - 1/4" Bit Sockets 10 Piece 1/4" SAE Hex Bit Socket Set includes: 1/16" - 1/4" Bit Sockets packaged on a clip rail.