I've bought mainly for the protection of my lens UV filter this and am absolutely satisfied so far.
The multi-coated glass fits perfectly in the frame and can be easily cleaned with a brush and cloth.
A loss of light intensity I could not find it.
As it should be, there is an internal and an external thread for additional filters to be mounted.
Only the packaging in its original box had something filters can be designed gentler.
The part has certainly been through a lot during transportation. The filter could be in plastic box
almost unpadded back and forth. However, one can assume that the filter actually
can withstand a lot if he survived this transport harmless.
So to me, there is a recommendation to buy!