The Resonance Transmission and Reflection Evaluation System uses a computer controlled tunable vacuum ultraviolet (VUV) light source for testing reflectance and transmittance of a sample. It delivers VUV wavelengths to samples and measures their spectral reflectance and/or transmittance with a solar blind PMT. Its modular design allows for quick and easy change of emission sources, detectors and sample wheels.This is an excellent system for quality control, fundamental research and development of VUV and UV materials, and with its small footprint and LabVIEW based software, the TR-SES 300 from Resonance Ltd. is an easy fit in almost any lab.