The 89403M C is a 25 mm diameter Multi Bandpass Filter, designed and manufactured by Chroma. This filter is part of the UVFS MAL-1965 material ID family and is available for purchase directly from Chroma's website, where it is currently in stock.
This optical component is classified as a Bandpass Filter, which means it allows transmission of light within a specific range of wavelengths while blocking other wavelengths. The precise wavelength that this filter is designed to transmit is 588 nanometers.
The filter is circular in shape, with a diameter of 25 millimeters and a thickness of 1 millimeter. This thin profile, combined with its circular shape, gives it a "Thin Lens" designation. The front and back surfaces of the filter are coated with Chroma's proprietary coatings, specifically the "chr 89403m" coating on both surfaces.