In an aquarium with no flow, fish and corals begin to die in as little as 4 to 10 hours. The VorTech Battery Backup is reef tank insurance in an aluminum housing. By adding the VorTech Battery Backup, your tank is insulated from power interruptions for up to 20 hours with the MP60wES, 36 hours with the MP40wES, and up to 72 hours with the MP10wES. Also links in with the Radion LED lights. Comes with 2 Cables.