Neewer Follow Focus with Adjustbale Gear Ring Belt for DSLR Cameras Such as Nikon,Canon,Sony/DV/Camcorder/Film/Video Cameras,Fits Shoulder Supports,Stabilizers,Movie rigs,All 15mm Rod Mounts Compitable with all DSLR cameras,camcorders.film cameras and video cameras.It can fit industry standard 15mm/.59" rod mounts(6mm for center to center distance) tightly.(ROD NOT INCLUDED) Use gear drive to adjust camera focus in a more accurate and smooth way. Easy to install and use. An adjustable gear ring belt is designed to fit wider range of lense diameters. Grooved knob for slip-free control.A white marking disk to mark focus point. It can be mounted from both sides for left-handed or right-handed photographers.