Filters are designed by their manufacturers to transmit or absorb different wavelengths of light. And they are widely used in scientific experiments and industrial applications where that change is necessary. 
VY Optics Photoelectric Technology Co.,Ltd. can supply a full range of filter. They are short pass Filter, long pass Filter, band pass Filter, ultraviole Filtert, infrared Filter, heat absorbing Filter, and color temperature conversion filters. We use material by China to Schott, Hoya, and other manufacturers to process them. Metallic films, colored glasses and thin dielectric films filter are all available per your requirements.

Specification of our color filter as follow:
Material:Filter Glass,BK7
Dimension: 4mm-160mm - 0.20mm
Squares/Rectangles:1mm-165mm
Thickness:0.5mm-4mm 
Thickness tolerance:+/-0.01mm-0.1mm
Paralism: Up to 3 Arc minutes
Edges:Fine 
Ground Flatness:Up to Lambda/10
Surface quantity: 80/50-20/10 Scratch/Dig