The Durus Focus Lever is a cool little device. Used with the Durus Focus Gears (which fit to virtually any lens), the Focus Lever attaches in seconds, providing an instant focus pulling device. It can also be fitted to the zoom ring of your lens when whip zooms are desired. The focus lever itself can be twisted clockwise to loosen, the angle changed and then twisted counter-clockwise to lock it in position. This piece is 100% CNC machined and no plastic parts are used.