Tekton Locking Extensions feature an easy-to-use locking mechanism. Push sockets or accessories onto the extension drive tang to lock them on, and pull down on the collar to release them. The extensions are made from 6140 chromium-vanadium steel with a 8660 nickel-chromium-molybdenum collar, and are chrome-plated for corrosion resistance. Deep knurling provides grip for turning fasteners, and grooves provide grip for attaching and removing sockets and accessories.