A set of three primary and three secondary colour acetate filters mounted in plastic frames (50mm x 50mm).Suitable for use in optical boxes etc. While not suitable for photographic work the acetate film is more robust than gelatine for general use.The set includes:Primary filters: red blue and dark green.Secondary filters: magenta yellow and peacock- blue.Visible Spectrum Data (Wavelengths):Red: 620 - 750nmOrange: 590 - 620nmYellow: 570 - 590nmGreen: 495 - 570nmBlue: 450 - 495nmIndigo: 420 - 450nmViolet: 380 - 450nm