I've become a huge fan of K&F Concept. It's hard not to consider the cost of this line of filters. This is the first filter from this line I've gotten, all the others have been either the Nano or top-line series. The filter is almost disappointingly light, especially in the 52mm size I got. It has very deep grooves that really make it easier to grip — and they don't add to the overall diameter, so if you have a slide-on cap or hood, they won't get in the way. It's also very thin, which is a good thing — but is also my only complaint about the filter — the internal thread (on the front of the filter) is too shallow to accommodate the OEM lens hood designed for the Nokton lens I use it with. It kind of holds it, but it does wobble and play a bit, so I'm baffled by that. I tested it with the ~10 year old German "pro" level MRC filter that's been on the lens since I got it, and it's visibly a better filter in terms of overall contrast. (K&F's elevation filters are even better in this regard.) And for that cheap price, you get a lens cap and sealed cleaning cloth. The lens cap I bought separately was also the first K&F product I used that I thought had a flawed design, and this smaller one is too — the recesses for your fingertips do have plenty of depth on the cap, but the surfaces you squeeze to use the cap are completely smooth, and I have trouble using it. I was able to fix that by gluing a very small (~0.02 x 0.06) strip of plastic along the side edges of the pinch points, which makes these work really well. So — even at 4 stars (a high rating from me), there are things I don't like about this filter kit. But I don't think the shallow threads will be an issue for most people, and getting a really good filter for so little is worth a star to me.