The Promax PROLITE-57 is a portable, high quality PON optical power meter. It is specifically designed to meet the rapid growth of FTTx market with PON (Passive Optical Network) technologies. It is capable to measure all three signals (1310 nm, 1490 nm and 1550 nm) that carry voice, data and video, so-called triple-play applications along a single fiber. PROLITE-57 can measure not only 1490 nm and 1550 nm optical signal, but also accurately detect and measure the upstream burst at 1310 nm sent from an ONU while the ONU is in the idle mode. The simple operation and accurate measurement make PROLITE-57 an ideal tool for PON (suitable for APON, BPON, EPON and GPON application) installation and acceptance test to ensure that they meet required standards, and service activation and troubleshooting.