Sunpak made in Japan,  by a major filter manufacturer,   The polarizers are very equal or better than most of the brand H and K. The enhancing series of filters are priced, very competitively with the other similar brands. The Sunpak C39 optical resin graduals come in large sizes at a good value

Tiffen UVP (Uv-Protectors) are solid glass filters, with no optical coatings. All other Tiffen filters Uv-1's and skylights are laminated (2 pieces of glass, with the laminate carrying the color or effects) and no coatings. For more Tiffen Information

B+W filters are solid Schott Glass, water type, crystal clear. No B+W filter has ever been made with green glass. and they never will, I hope. Quality should always have its standards and the word quality should be more than just a word on a box. Most of all B+W filters have mono coatings on both sides (in some places called double coatings, the double = one on each side)
Please note:  All of the B+W filters 2filter.com sells are mounted in B+W German brass rings only , In markets around the world you can purchase B+W filters in mounting ring materials other than brass. The boxes and the filters look the same in a picture. When you feel the quality of the brass mount you know you have the right one. The B+W MRC coatings are the quality that B+W customers need , the B+W MRC coating is as good as it can be 99.5% transmission.  the MRC coating is on all the Multicoated polarizers we sell.