I use this HOYA PRO1 filter on my picture optical range for over a year. I am very happy with the mid-range of HOYA (good quality / price): easy installation on my optical CANON (screws and unscrews easily), the protective cap is normally hangs on, cleaning is correct and the Contrast is good. It is permanently installed to protect the front glass of the lens. It comes in a sturdy protective box. Of course I prefer the quality of the range HOYA HD (better cleaning and made slightly more neutral), but the same filter costs almost double, with reference B + W brand but price is not the same ...