Neewer Follow Focus CN-90F with Gear Ring Belt for DSLR Cameras of 65mm-103mm Lens Diameter Such as Nikon,Canon,Sony DV/Camcorder/Film/Video Cameras,Fits 15mm Rod Mounts,Shoulder Supports Completely gear driven design for slip-free and accurate movement. Ideal for video taking with HDSLR cameras such as Canon EOS 600D, 60D, etc. Adjustable locking system. Gear drive can be mounted from either side Improved design, with a pair of stops on the ring for adjustable focus indication. You can control follow focus in desired range by setting the stops, and so for desired focal lengths. Compatible with all DSLR cameras, video cameras, HDV, DV, specially for HDSLR camera with movie function.