The FL635-10 from Thorlabs Inc is a Optical Filter with Wavelength 600 to 694.3 nm, Center Wavelength(CWL) 635 nm, Bandwidth (FWHM) 10 nm, Blocking Wavelength 200 to 1150 nm, Filter Diameter 25.4 mm (1 Inch). More details for FL635-10 can be seen below.