SuperKrome finish provides long life and maximum corrosion resistance. Through-hole design: simply pop the old bit out and insert a new replacement bit . New bit holder design is 9 times stronger and helps prevent the bit from slipping out of the socket while working. High strength, S2 steel bits. Lifetime warranty9 piece set is made in the U.S.A. Bit sockets feature SK's high polish SuperKrome finish, which provides for long life and maximum corrosion resistance. Through-hole design makes it easier to replace worn or broken bits. Bits are manufactured to rigid standards using high strength S2 steel. Sizes include: 3/8" Drive - 5/32", 3/16", 7/32", 1/4", 5/16", 3/8" Hex Bit Sockets; 1/2" Drive - 1/2", 9/16", 5/8" Hex Bit Sockets. Packaged in a molded plastic case.