The Hoya 37mm Fusion One Next PL-CIR Filter is an update of the HOYA FUSION ONE series and continues to benefit photographers in a variety of shooting conditions by incorporating high-quality optical glass with HOYA's water repellent and stain resistant Super HMC coatings which make filter maintenance easy whilst providing reliable protection for the camera lens. The word "ONE" in the naming of this series is maintained as legacy of HOYA PRO-1D, in memory of its contribution to photographers' creativity, with the belief that this new series will serve well for many decades ahead. Features of the Hoya 37mm Fusion One Next PL-CIR Filter 18 coated layers provide ultra-high light transmission Stain resistant - protects from fingerprints and smudges Water repellent - easy to keep filter clean For permanent lens protection Ultra-smooth frame rotation HOYA's professional grade optical glass Exclusive one-piece, low-profile filter frame with front filter thread Made in Japan FUSION ONE NEXT filters have been designed to match the rigorous standards and optical capabilities of modern, high-resolution lenses. They join the HOYA filter line-up as a fusion of all the highly valued specifications: Multi-layer coating, ultra-high light-transmission, professional-grade optical glass and a low-profile filter-frame. They additionally incorporate stain resistance and a water-repellent coating. Light rays which are reflected by any surface can become polarised and polarising filters can be used to select which light rays enter your camera lens. CIR-PL (Circular Polarising) filters allow you to remove unwanted reflections from non-metallic surfaces such as water, glass etc. They also enable colours to become more saturated and appear clearer with better contrast. This effect is often used to increase the contrast and saturation in blue skies and white clouds. HOYA's polarising filters do not affect the overall colour balance of a shot. For more Hoya products see here.