Compatible with Canon, Nikon, Sony, and other DSLRs, camcorders, DV, and video cameras. Fits industry-standard 15mm rod mounts and a 60mm center-to-center distance. Easy to attach and detach. The geared drive allows for more precise and smoother adjustment of the camera's focus. Gear ring belt: Suitable for lenses with a diameter less than 100mm. Non-slip design with a grooved knob. White plastic marking ring for focus markings.