Allows extreme focusing lenses to be geared and used with follow focus industry standard 0.8 module.  Gear ring with Unique locking method to prevent loose rack, works on any prime or zoom lens.Horizontal and vertical adjustment control.Two hard stops available.Custom fit slide mounting mechanism to match any lens diameter. Most of the time, Cinematographers or photographers missed focus mark when shooting intricate camera moves or lost control grabbing for the traditional lens focus ring and not quite making it, In such cases this Followfocus with SIX gear rings and speed crank helps hitting focus marks much easily.