Well, If you buy cheap you pay twice as the saying goes. This filter is poorly constructed. The glass is not a tight fit in the holder, being so loose that it will spin. There is also far too much play front to back within the holder & the result is a filter that rattles loudly when handled & on the camera lens. It may not impair performance but it is EXTREEMLY ANNOYING!!!!
Very very dissapointed.
Since posting this review I discovered an inner Ring with two small groves which when rotated clock wise with a pen tip tightened the Glass in the filter & stopped the rattle.
Now a very useful filter (Just poor quality control)