WIZ550SR is the serial to Ethernet module using W5500 & Cortex-M3 MCU.
WIZ550SR does not contain RJ45 because very small size type. WIZ550SR provides the user Interface 2.00mm Pitch Pin header.
WIZ550SR is the protocol converter that transmits the data sent by serial equipment as TCP/IP data type, and converts back the TCP/IP data received through the network into serial data to transmit back to the equipment.
WIZ550SR does not contain RJ45 because very small size type. WIZ550SR provides the user Interface 2.00mm Pitch Pin header.
If you use the interface board for UART, you can easily connect the module to any serial device.