ES-551 is a part of Brainboxes, which is an industrial Ethernet connectivity solution. It is a 5-port industrial Ethernet switch that provides five 10/100Base-T ports to connect Ethernet devices such as computers and other devices. The switch is designed to operate in harsh environments and can withstand wide temperature ranges, and is certified to various industry standards. It also features advanced features such as port-based VLANs, SNMP support, port mirroring, statistics, and port configuration. Additionally, the switch supports event logging, which allows it to be used in secure industrial networks.