• One of a comprehensive range of Premier Hand Tools, suitable for daily professional use. • Chrome Vanadium 6150 steel bits hardened to 52-53 HRC and tempered for added strength. • Set includes 3/8" and 1/2"Sq drive to 10mm hex Chrome Vanadium steel bit adaptors. • Supplied in storage case with inclined tray for quick and easy bit selection. • Lifetime guarantee*.