[Excellent unique lock mechanism] The biggest stress when shooting filters with a smartphone was “misaligned clips” and “trouble attaching”, but this product solved that perfectly. It is not an open leg like a typical clothespin, but it has a structure where the arms rise and fall in parallel. Therefore, force is always applied perpendicular to the lens surface of the smartphone, and it is wonderful that the filter adheres perfectly without floating. The unique push lock button is also excellent, and positioning can be performed simply by pressing and sliding, and when you release your finger, it is firmly fixed. [Use the equipment you have on hand] It's more convenient than you can imagine that the 58mm diameter filter for single-lens reflex cameras that you had left over can be used directly on your smartphone. There is no need to go out of the way to buy a new magnetic filter etc. for smartphones, etc., and the range of shooting expanded all at once, such as turning off reflections on the surface of the water with a PL filter and cutting the slow shutter with an ND filter. The screw cutting part is made of metal, so there is no need to worry about it being scraped even if you put it on and take it off frequently, which is also a good impression. [Points of interest] The depth of the clip may be slightly severe compared to the large camera units (overhangs) seen in high-end smartphones these days. There was no problem with my model, but if you wear a thick shockproof case, etc., there is a possibility that the pinch will be shallow, so be careful. Also, although the aperture of 58mm is large enough, vignetting may appear at the four corners when using an ultra-wide-angle lens, so in that case it is an operation to avoid it by zooming slightly. [Overall Review] This is a shooting aid tool with a very thoughtful design that sets it apart from a simple plastic clip. It's lightweight at only 19g, and comes with a strap just in case, so it's not a burden even if you keep it hidden in your luggage during a shooting trip. If you have an SLR or mirrorless camera and know the fun of filter work, you should be extremely satisfied as an accessory you can get in this price range.