Don't understand how there are so many reviews saying this CPL doesn't work, or is poor quality. The one I receieved (77mm) was clean and smooth turning. It really removes alot of reflection. In fact if pointed at a computer monitor, it can turn the monitor completely black on its maximum position which is quite impressive. I did make my own little mark to indicate the maximum/minimum positions as it does lack that. I however only paid 28$ cad (as opposed to the listed 42.12$ cad) for this filter NEW fulfilled by amazon warehouse deals because I assume someone ordered it and canceled it. It still arrived in undamaged packaging and not a fingerprint on the filter. Really really glad I checked the 'new and used' section to save about 15$!