Cisco CAB-SS-SURGE= Blue surge protector

Cable Adapter Surge protect f/ SMT series Surge events, including ElectroStatic Discharge (ESD) and lightning surges, are common in many parts of the world, especially during electrical storms. These energy surges can damage electrical equipment and lead to network down time. Cisco surge protection cables for Smart Serial interfaces help protect your network from down-time due to these surge events. If you protect your router from surges via the power input (surge protectors, Uninterruptible Power Supplies, or power conditioners), you should also protect your router serial interfaces.