Features Removable Cine-Style Lens Gear Ring, For Lenses with a 72 to 73.9mm Diameter, Slide-On Mounting, Compression Fit, No Dead Spots or Rotation Stops. The LuxGear Follow Focus Gear Ring from Cool-Lux is a seamless lens gear for lenses with a focus-barrel diameter of 72 to 73.9mm. It features standard 0.8-mod/32-pitch geared teeth that makes it compatible with cine-style follow focus systems. To find the appropriate sized gear for your lens please see the lens compatibility chart and sizing tools accessible by clicking on Guides & Manuals.