This DataLine Surge Protector protect your Token Ring port against power surges. Perfect for MAU, repeaters or other network devices. It has extremely sensitive, state of the art avalanche-diode technology. It has high speed throughput, automatic reset after surge, rugged & stylish with easy In-Line installation and negligible signal loss. (Connectors: 4Wires Terminal Block; Surge Capacity: 18.0v)