Hello, I just purchased an adjustable ND filter for my Osmo.  In one filter, it will do anything from ND2 all the way to ND400.  It's pretty amazing, and I have no idea how it works, but it does.  The one drawback is that it seems significantly heavier than the regular screw on lens, so I'm wondering if that weight will damage the X3 motors over time, or if it's safe to use?  I did test it out, and it seems to work fine, but I don't want to damage my Osmo by overloading it.
Here's what I purchased. http://r.ebay.com/FzQoFQ

Unable to compare weight no information on the link supplier states compatibility how much heavier is it.Cant see it having an adverse effect.Check the weight difference to be sure

That filter will be fine for the osmo

It looks like a very dedicated one, hope it works well with the Osmo.
Thanks for the information!

At the same time, please also have a look at our official ND filters: http://store.dji.com/product/inspire-1-filter-kit