The JDSU OLS-55 (BN 2279/01) is a smart handheld optical laser source designed for accurate fiber optic testing, installation, and maintenance of single-mode networks. Operating at 1310 nm and 1550 nm, this unit provides high output power stability, adjustable output levels, and automatic wavelength identification when paired with compatible JDSU power meters. Its rugged field-ready design, intuitive graphical interface, and support for CW and modulated modes make it ideal for insertion loss testing, continuity checks, and end-to-end fiber link verification.