Vktech&reg; Lens Gear Ring Belt w/t Metal Hand Grip for Follow Focus DSLR Rig Camera Material: High quality Aluminum alloy, ABS Whole length: 36cm Gear module: Global engineering standard 0.8 Built-in Stainless steel screw, in accord with the global standard size Suitable lens size: 49mm, 52mm, 55mm, 58mm, 62mm ,67mm, 72mm, 77mm, 82mm