Completely gear-driven design for slip-free, accurate, and repeatable focus movement. Adjustable slide-mounting mechanism to fit large range of lens diameters, including video camera lenses. Industry-standard 15mm lightweight (60mm spacing) rod mount. Driven gear capable to install on either side which is suitable for right or left handed shooter. Made of durable anodized black aluminum and ABS. Compatible with all DSLR cameras, video cameras. Suitable the diameter of the lens from 52mm to 86mm.