This special C-Mount adapter incorporates a high quality IR cut filter. Highly recommended for professional users that require best color reproduction when using the ProScope HR/HR5 with a microscope, telescope, or borescope. The IR cut filter is made from high quality BK7 optical glass and has a transmission range of approximately 380nm to 700nm, the visible light spectrum. Invisible wavelengths, that can still be seen by the high quality HR series imagers, are removed for best color reproduction in critical applications.