Warning to potential Atik purchasers, you are unlikely to receive support from Atik on these forums. Here's a clear example- I posted this very simple request months ago, and followed it up with emails directly to not only Atik support but also directly to atik principals, and never heard back from anyone. I bought my 11000 second hand and so I can't complain about that, but the filterwheel was purchased new and I would have thought that atik would want to take care of "new" customers. In this hobby, failure to stay on top of customer needs post-purchase can only hurt market share, unless I'm too late to gripe and Atik is already facing liquidity issues and bankruptcy. Either way, this has been my experience, for whatever it's worth.