Black Box  Surge 4 Wire Terminal Strip Protector SP603A RS-232,422,423,485 & Ethernet.

Black Box data-line protectors couldn't be easier to install. Quick-Connect Surge Protector can be easily installed with Quick-Connect connectors - right at the port - just strip the cable and insert. Spring-loaded design prevents wires from loosening, corroding, or becoming brittle. Low shunt capacitance is used to reduce signal loss. The unit features state-of-the-art avalanche diode technology and provides protection for RS-232, RS-422/423/485, Token Ring, and 10BASE-T. It keeps your network and communications devices (I/O cards, controllers, programmable logic controllers, modems, CSU/DSUs, hubs, and multiplexors) up and running.