<p>This geared ring is purposed to be installed on FM LENS.</p> <p>Installation is very simple - just put the gear over original ring and secure three set screws by means of included hex key.</p> <p>If you don't need the gear anymore, removing is very simple as well - loose three set screw and pull the gear off the lens.</p> <p>Installation/removing takes about one minute, and doesn't require any special skills.</p> <p>Dimensions:</p> <ul> <li>Inner diameter - 88.3 mm;</li> <li>Outer diameter -107 mm;</li> <li>Thickness - 32 mm.</li> <li>Mod - 0.8 mm (pitch 32).</li> <li>Weight - 240 g.</li> </ul>