AK219 Sealey TRX Star Spline Hex Bit Set 42pc 3/8" 1/2" Square Drive Car Garage (NEXT DAY DELIVERY)• 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.