The filter is really good, it seems to be a real 10 stop filter (some ND1000 are only 8-9 stops, which makes shutterspeed calculations hard), it is reducing light in both Visible and Infrared light (has been tested on a full spectrum camera used for Infrared Photography), so you will not have a nasty discolouration in the sky as with other ND filters, but you will get a slight blue colour cast, nothing that can not be fixed in post process with the white balance tool, but I highly recommend doing a white balance setting with the filter on to get accurate colours, especially if you are shooting in JPG. I did not see any reduction in detail (see the 100% or 1:1 crop). It easily screwed on my lens and step up rings as well. It has a nice grippy area which I find giving a much better grip than other filters. One thing I'd like to mention is the case it's coming with has a nice locking mechanism and also two carve outs to be able to easily remove the filter from it's case, actually it's one of the best cases I've seen, beating the nice metallic cases from Gobe, which does not close well with larger filters.
If colour cast is a critical issue for you then this filter might disappoint you with it's blue cast, in that case I recommend Haida's NanoPRO ND1000, which I unfortantely lost, but that has virtually no colour cast at all, but nearly triple the price.

I am very satisfied with the ND filter. Can't see any color cast and the price is right too.

Easy to use. Watch a couple of your tube videos on how to use and this picture made it worth the purchase.

Best suited for long exposure pics.

This 10 stop ND filter is a lot of fun. No vignetting that I could see, although the edge of the filter is visible at the widest lens setting, likely because I’m using it with a step-up ring glued to the front of my Canon G7X mk.ii!

This filter is absolutely amazing! Quality for a fraction of the price! I used today and it worked flawlessly! Totally worth it!

I was using a Canon 6D w/ 24-105 F4

good

Came in two days price was perfect more then happy with the filter

After reading and looking at a number of tests, in which the filter mostly performed better than expected for monitoring the testers, I bought it. The filter fulfills its purpose at least 99% and delivers a top result on my Canon 80D. I am glad I bought this one and would buy a filter from K & f again at any time.

I am a complete newcomer to long exposure during the day. And I have to say that I am very excited. For me it is definitely sufficient and an alternative to high-priced angular filter systems. I'm only doing it as a hobby and that's enough. Think the pictures speak for themselves. Can unreservedly recommend the ND filter!