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 storage 10 Piece 3/8" and 1/2" Drive SAE Hex Bit Set includes: 5/32", 3/16", 7/32", 1/4", 5/16", 3/8", 7/16", 1/2", 9/16", and 5/8" Sockets packaged on a clip rail.