All filters are ”Made in the USA” from high quality ground optical glass. Tiffen’s ColorCore process ensures consistency from filter to filter, year after year. They are only filters that match the Kodak Wratten series in light transmission and color curves. We have the only UV Haze filter to match the photometric specifications of Kodak Wratten filters. These filters reduce the UV portion of the spectrum by greater percentage than any other filter on the market.