With modules starting at just 3.5 mm wide, the Termitrab Complete surge protective devices (SPDs) can protect as many as 572 signals on 1 m of DIN rail. In addition to this ultra-narrow option, the SPD line includes variants that meet many specific measurement and control needs. The range includes SPDs that use optical monitoring capabilities to troubleshoot and diagnose a system from any location. Local and remote status indication simplifies maintenance. Some modules in the line come in a pluggable format so users can remove and replace devices without having to undo or redo connection wiring.