OPM-500, a compact, handheld tester, provides stable laser light power measurement in five different wavelengths for fiber cable testing. By measuring the most popular wavelengths, 850nm, 980nm, 1300nm, 1310nm, 1490nm and 1550nm, the OPM-500 is an ideal tester designed for active optical fiber networks. When used in conjunction with any third party optical light source or the OLS-200 from CTC Union, the actual optical attenuation of a fiber link can be determined during pre-installation of active devices or for troubleshooting in-field fiber problems.