I like the size of this one, and K&F has good quality filters(depending on the tier they can be really good or ok). that I also use for my cameras. I have the Tamron Sony lenses and they use 67mm so it's nice and fit nicely with those along with others. This is perfect because I use this in conjuction with a step up ring on my phone with this phone clip for my filter sets and I can get some awesome filter fx. I have some gradient and ND filters. I've also used one of my variable NDs 67mm on the phone with it. Another way to have fun with photography without all the gear.

I've been a fan of K&F filters and accessories for some time now and have come to appreciate the brand's durability and quality. Most of my lenses live their lives with K&F UV protection filters on the front. Like many others, I've started to focus more energy on taking advantage of these features, not to mention portability, as the quality of mobile phone images and videos has improved to near-professional quality levels. In both videography and photography, whether with a full-size camera or a high-end mobile phone, I find a CPL filter indispensable. It also has the effect of neutral density. In the hand, the K&F Concepts Magnetic Circular Polarizing Filter System gives the impression of quality. Between the matte black finish, the 52mm magnetic adapter ring, and the reflection of the rich multi-coatings, it's an impressive filter. Interestingly, despite the fact that the adapter and filter are magnetically attached, the CPL still rotates freely as needed to adjust the angle. That must be magic. The only disappointment with the system for me is the lack of usable threads on the front of the CPL. I prefer lens hoods and would love a way to attach them. Or to have the option to mount another filter or step-up ring onto the system. However, step-up/down rings with appropriate 52mm thread can be attached to the threaded adapter ring. For example, a 49mm — 52mm step-down ring allows the 52mm CPL to be used on a 49mm threaded lens. On the other hand, the lens I showed in the pictures takes 52mm filters and its built-in sunshade fits well with the 52mm K&F Concept Magnetic System, but the lens' front cap does not. I checked the K&F Concept store and they have a number of other magnetic filters, filter sizes and adapter ring combinations in their magnetic ecosystem, most of which include a magnetically attachable front lens cap, including circular polarizers; why they don't include one with that combination I wouldn't know, but I think they should. The convenience of the system is negated if, to protect the font of my lens, I have to twist out the adapter ring to put it on a lens cap. I didn't notice anywhere in their Amazon store that a compatible magnetic lens cap is sold separately. In my view, a complete system, and I'm not just referring to K&F Concept in this regard, would include magnetically attachable lens caps and lens hoods as part of the ecosystem. Or failing that, the front threads on the attached filter or the corresponding adapter rings that are the same size as the rear threads on the adapter, allowing for a more versatile system and one that would accommodate the screw-on filters currently used by users. In any case, I have full confidence in the quality of K&F Concepts filters and their products in general. They are a reliable company that stands behind their product lines. If you are interested in any magnetic filtration system, including this one, I suggest checking out the K&F Concept Amazon store for all the available options. Enjoy.

However, a sensible filter with 6 f-stops can be difficult to attach to the lens because I used a step-up ring.

They screw on pretty smooth it have a quality threads, and it work just fine. Perfect for someone who's only going to be casually using their step up rings, I am a professional photographer & I was looking same filter Ring Adapter & I order this product which is very helpful for me when I use multiple filter with my Nikon 5300 camera lens. During photo-shoot many time we have to change camera lens along with filter also, so using this ring it is very helpful for me, these rings get there job done, and don't get stuck. Please note - these are step-Up rings also have Step Down Rings total 18 rings.

ordered the K&F Concept Step Up Ring 72mm to 77mm to be able to use my 77 filter as well. The ring is cleanly processed and the threads are cut absolutely cleanly, so it can be screwed onto the lens and the 77 filter onto the ring without any problems. No complaints, everything great. I definitely recommend the ring.

This step up ring does the job well. If like me you have protective glass over the lens it might remove it along with the step up ring. But don't worry, they can easily break up afterwards. Can't say for long term use yet, it all depends on how high quality aluminum is, only time will tell. For now, I'm happy with being able to use a larger ND filter on more lenses.

K&F Concept Step Up Ring for lenses, 58mm to 62mm, just under 5€ With adapter rings, only the precision of the production counts so that the threads mesh well. The ring from K&F Concept fulfills this very well. Now I can also use the filters from my 55-200mm tele. You should only note that if you leave the adapter on the lens, you may need a larger lens cap, as the smaller one no longer grips. Conclusion: Everything in order, price is right. 5 Stars

Normal step up ring that works