OTDR Optical Time Domain Reflectometer with 40dB 1625nm LC/PC Connector, Ethernet Monitoring Interface, Pluggable Module OTS3000-OTDR is a kind of functional card in optical communication integrated platform. It provides external Ethernet port for the user to integrate the secondary development conveniently into the original monitoring system. OTDR can work with other function cards (such as OSW, LSU, and OPD) together to construct the complete cable monitoring system. https://www.glsunmall.com/product/ots3000-otdr-optical-time-domain-reflectometer.html