Seamless™ Follow Focus Gear for Asahi Opt. Co. Super-Multi-Coated Takumar 20mm f4.5 LensThis gear fits the Asahi Opt. Co. Super Multi Coated Takumar 20mm f 4. 5 lens. 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 you can if you like. Each gear comes with a lifetime