Hi, I bought these items: http://www.ebay.com/itm/390740971990 http://www.ebay.com/itm/261354115278 I removed the Polarizing filter, and screwed in the ND 8 filter. In combination with the CM3000 Gimbal (the mount of the Gimbal fits around the lens) you can't get the filter holder close enough to the body so there is a lot of vignetting in wide mode. Even if you fit the filterholder + ND filter without the Gimbal, there is still a little vignetting. Haven't tried, but I guess in other modes as wide things will be ok. The filter holder feels very secure. The Gimbal did not seem to have trouble with the extra weight of the filter + holder when moving the Phantom by hand, haven't tried in flight. The glass quality of the ND filter seems pretty good in a short test I did. If someone knows about a ND filter solution without vignetting in wide mode, please let me know!