Whether you love or hate this K&F Concept Mount and Circular Polarizing Filter depends on the type of case you use and whether it has MagSafe capability. I'm not willing to use my phone without a case, and the mount doesn't attach as well if your case doesn't have a MagSafe pass-through. In addition, any "camera bump" coverage in your case may cause it to sit cockeyed. So I don't expect to keep this attached to my phone, but rather to pull it out for use when I think that my photos will benefit from a CP.Here's how I'd rate the different characteristicsQuality: Excellent - Fit and finish are excellent. No manufacturing issuesFunctionality: Excellent - The MagSafe design makes it very easy to use the Circular Polarizing Filter when composing photosFit: Below Average (when using case), Excellent (with no case) - Fitment is an issue when using any of the 5 cases I tested this with (see pic showing slight misalignment). It works very well if you rock your phone without a case.Ease of use: Excellent - Just place it on the MagSafe ring and align it with the camerasImage Quality - Excellent - This CP filter does an excellent job of improving contrast and decreasing glare without decreasing image qualityOverall I think that this merits 5 stars despite my reservations about fitment when using a case. I plan to use some of my spare MagSafe magnetic rings leftover from previous cases to try to even out and better align the mount.