APC BML3-A Black surge protector

Surge Protective, 600V 3PH, 120 kAmps, Black Themal overload protection
Prevents thermal run-away when metal oxide varistors (MOVs) become damaged, or when a continuous overvoltage condition exists.

Protection Working Indicator
SurgeArrest will warn you if its circuitry has been damaged by heavy strike or power line surge and it is unable to provide 100% protection. If still under warranty, APC will then replace your damaged SurgeArrest free of charge.

Lightning and Surge Protection
To prevent damage to your equipment from power surges and spikes.