These Sonic's wobble extensions are made from tough Chrome Vanadium steel for strength and for fighting off corrosive materials like rust. They can be used as a regular extension by pushing the socket all the way onto the extension, or you can pull the socket out just a bit to get several degrees of angle. A hex head on the top of the extension provides a place for a wrench, when needed, and knurling on the shaft provides additional grip for your fingers.