All of the AFS power meters are the perfect tools for measuring optical power, loss (attenuation) and optical return loss in any system, it is just a matter of picking the right instrument for the application. All meters are calibrated at industry standard wavelengths (NIST traceable) for both single-mode and multimode transmitters. All detectors are potted in a threaded housing for versatility and allows the user to interchange adapters for numerous connector types. The OM100A series meters are a low cost series of power meters for the technician who wants a high performance meter. All power meters now come with protective rubber boot.