This is Single Port RJ45 Connector with LED. These are through-hole RJ45 connectors with PCB mounting posts. These 12-pin connectors are commonly used in conjunction with Cat5, Cat5e, and Cat6 Ethernet cables. Because Ethernet cable is so ubiquitous, these are awesome for projects where you need to string a lot of modules together over a distance. These RJ45 Connector has LED indicators to let you know that data is being sent.