https://www.iberoptics.com/en/optical-filters/alluxa_aua-unbp-770-1-od4-2652.html
Alluxa Ultra-Narrow Bandpass Filter: centered in 770 nm, FWHM of 1 nm, OD4
Alluxa Ultra-Narrow Bandpass Filter, 770 nm center wavelength, 1 nm FWHM and OD4 blocking. High performance with the narrowest bandwidth response.
ultra narrow bandpass