Seamless™ Follow Focus Gear for Sigma 70-200mm f2.8 DG SPORT LensThis gear fits the Sigma 70 200mm f 2. 8 DG SPORT lens. It will only fit the DG model lens. If you need the DG DN model, click here. It is designed specifically to fit this lens and is compatible with any standard 0. 8 Module follow focus. The gear sits 3 6mm high off the focus ring of your lens for a clean, low profile gear that slides smoothly onto your lens and into your current lens case. The gears do not have to be removed after each use although