Patented bit holding system forces bit surface to opposing side for maximum retention Chrome sockets; heat treated for durability and service ability S2 and Alloy steel bits Packaged in patented impact resistant "Slide Rail" System for ease in socket storage7 Piece SAE Hex Bit Socket Set (1/2" Drive) includes 5/16", 3/8", 7/16", 1/2", 9/16", 5/8", and 3/4" Bit Sockets packaged on a clip rail.