Material: completely metal. (Gear part is of brass and steel,other part is of aluminum. * This Rail Base Plate has a Quick Release plate that enables the quick attached of the camera and easily slides into the adapter. * The plate comes with both 1/4" and 3/8" camera mounting screws. Hence the large variety of cameras can be used with this Rail System. * Follow Focus mounts onto industry standard 15mm rods (60mm center to center difference). With Adjustable locking systems, can be mounted from both side.(Works for both right-handed and left handed) * This set includes flexible gearbelt can be used with any zoom or prime lenses with a wide range of lens diameters(any size from 46 to 110mm)