A super quality set of super lock sockets in both 1/4″ and 3/8″ drives. Manufactured by US.PRO Tools (formerly known as Bergen Tools), one of the more respected hand tool manufacturers on the market. Manufactured from Chrome Vanadium Steel (CR-V) for longevity and durability and helps resist abrasion, oxidation and corrosion. Super Lock sockets use a unique design meaning the greater the torque applied, the more they will grip the nut or bolt. Very handy for removing stubborn, worn or rusty nuts and bolts. Sizes are as follows: 1/4″ Drive: 6, 7, 8, 9, 10, 11, 12 and 13mm. 3/8″ Drive: 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18 and 19mm. Suitable for both the professional or occasional user alike.