The 485ELC is low capacitance, 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 interruption of service. The 485ELC is designed to protect data lines, transmission lines, timing and control interface circuits from common-mode (line-to-ground) or differential (line-line) transients. Terminals 1 & 2 and 3 & 4 are designed as line pairs. A transient voltage suppressor is connected across each line pair for differential mode protection.