The TEL185B/E is a two-stage transient voltage protector the provides primary and secondary protection against lightning, inductive switching and electrostatic discharge (ESD) transient threats. The first stage diverts the transient current through the ground terminal return path and the second stage clamps the voltage to a safe level without interuption of service. The TEL185B/E is designed to protect telcom lines from common mode (line-toground) transients. There are four (4) independent lines referenced to the ground terminals.