1/4 in. Drive 12 in. Auto-Flex™ Extension AutoFlex™ universal hinge articulates under spring tension providing semi-rigid directional control and accuracy.12 in. length 1/4 in. drive extension allows easy access to hard-to-reach areas.Spring loaded detent keeps sockets secure during use.Knurling on handle for excellent grip in oily conditions.Constructed of chrome-vanadium steel.AutoFlex™ is engineered to spring back to center making it perfect for fitting into tight spots.Unique professional feature of AutoFlex™ spring loaded design which prevent joint falling to one side 66112