Attaches directly to any camera via tripod mount, no rails needed. Adapter included to attach to 15mm rods * Completely gear-driven design for slip-free, accurate, and repeatable focus movement * 1:1 gear ratio allows smooth movements for still and motion picture 35mm lenses * Adjustable slide-mounting mechanism to fit large range of lens diameters, including video camera lenses * Gear drive can be mounted from both sides for left or right hand use