This is a set of the Nano-K series CPL filter, which is an introductory K&F Concept filter, and a smartphone clip. Previously, was used, but the filter itself is the same as that, and the clip structure seems more sophisticated (this product opens in parallel, but the conventional product opens like a clothespin). Also, the quality of the case has been improved, and a strap is now included. The CPL filter is a basic model that is not coated to be waterproof or scratch-resistant, but the effects of polarized light can be clearly felt. The rotation of the ring is slightly heavy, and there is almost no unintended shift, and I personally like the adjustment. Although the clip has been improved from conventional products, frankly speaking, the feeling of use hasn't changed much. The maximum width between the receiving side and the filter side of the clip was about 14 mm, so be careful when wearing a smartphone with a thickness higher than that, a smartphone with a protruding lens unit, or a thick case. Also, it's not that compatible with smartphones where the lens unit is extremely close to the edge or smartphones that use a camera bar with a full width, such as the Google Pixel 6 to 8 series (it can be used, but it is at a level where you need to be careful about the direction you wear it, etc.). The case looks pretty good and has pretty good protection, but personally I wanted to attach the strap to this case instead of a clip. Considering that [ASIN: B0DZ1R5KWK filter alone] is sold for around 2.5,000 yen, it's quite a bargain that comes with a smartphone clip and carrying case for an additional 500 yen. It's limited to those using a 67mm diameter camera lens, but it would also be helpful to be able to reuse it. However, as pointed out in the review of the filter alone, the protrusion of the filter frame is low, and the lens cap is not good. If you are considering using it in combination with a cap, you may want to consider it carefully.