Features:Spring loaded ball bearing on head holds sockets securely.This kit is applied to your impact drive or drill bit, and allows you to replace the ratchet with an electric tool.Each has been quenching heat treated, sturdy and wear resistant.Change your hand socket set into a driven socket set.This set is perfect for your impact driver or drill.The 1/4 inch hex shank fits all quick change chucks as well as standard drill chucks.Specifications:Material: Chrome-vanadium steelColorful circle: aluminum alloyHex Shank:1/4" (6.35mm)Quantity:3The hexagon handle can be converted to square headType:1/4*1/4*65mm:1/4"hex shank- - 6.35mm square head3/8*1/4*65.8mm:1/4"hex shank- - 9.4mm square head1/2*1/4*68mm:1/4"hex shank - -12.6mmsquare head Package Included:3 x Screwdriver Extension Bar Adapter