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 T8, T10, T15, T20, T25, T27, T30, T40, T45, T47, T50, T55, and T60 Torx Press Fit Sockets13 Piece Torx Press Fit Set (1/4", 3/8" and 1/2" Drive) includes: T8, T10, T15, T20, T25, T27, T30, T40, T45, T47, T50, T55 and T60 Torx Press Fit Sockets packaged on a clip rail