The Manfrotto 454 is a focusing rack which allows fine focusing control at close distances. At this point, focusing with the lens becomes difficult or impossible, and the solution is to move the complete camera/lens assembly backwards and forwards. A focusing rack enables precise focusing to be achieved easily and quickly. The 454 uses a worm drive which can be disengaged to allow rough initial positioning, and allows 120mm travel. It has 1/4" and 3/8" base sockets. Two can be mounted at 90° to each other to allow lateral as well as fore and aft adjustment.