Apex hex extensions feature a male 1/4", 5/16", 7/16", or 5/8" hex drive shank on one end, and either a 1/4", 3/8", or 1/2" male square drive on the other. Use these handy extensions with your favorite female drive power tool to increase the reach of your impact sockets. Apex hex extensions are offered in 1-3/8" all the way up to 15" over all lengths (OAL) to ensure your fasteners are never out of reach. A handy pin type retainer keeps impact sockets securely attached to the extension during operations. Lastly, as with all Apex fastener tools, these high quality extensions are made in the USA.