The Focus Lever attaches to the Durus Focus Gears (sold separately) 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. The Durus Focus Lever carries a lifetime warranty.Please note that you will need to order at least one Durus Focus Gear with the correct length spokes for your application.