eSource Optics Custom p/n 1201BBVUVBS: Unmounted and Open-Faced Broadband VUV-UV Beamsplitter designed to provide 40% to 50% average Reflectance and Transmission over the 170nm to 300nm VUV-UV wavelength range @ 45 degrees Angle of Incidence (AOI) Unpolarized.12.7mm Diameter x 1.0mm thick as follows: