Fotodiox Pro 145mm Slim Multi-Coated Circular Polarizer (MC-CPL) Filter - Pro1 Multi-Coated CPL Filter (works with WonderPana 145 & 66 Systems) Premium grade optical glass filter; high quality, single threaded, slim multi-coated CPL filter. Premium grade anodized aluminum ring; 145mm x 1mm standard filter thread Darken the skies and add contrast to clouds for better seperation and saturation. Minimize or eliminate reflections from water, windows, wet leaves, glass and eyeglasses. 24 Month Manufacturer Warranty