This customized filter rail is designed for M.Zuiko 7-14mm and is supposed to working with the M.Zuiko 7-14 filter adapter for Lee system
You can use this rail with up to two filters without getting vignette at almost any rotated position with focus further than 3m.
Another rail for another purpose is available here
This rail could be used for other ultra-wide-angle lens, however, we had yet test the usability.
The linking bar between the two rails are just for production cheaper, please cut them before installing it on the holder. If they breaks up during the production, the rails will still be useble, however in this case, Shapeways crew will ask you if you still need it, please tell me yes.