The IOTA ILB CP05 HE A constant power emergency LED driver enables the existing LED fixture to deliver emergency illumination for 90 minutes in the event of a loss of normal power. IOTA’s patented constant power design makes it easy to determine actual emergency lumen levels – simply multiply the emergency driver’s output wattage by your fixture’s ‘efficacy (ie. lumens per watt.). Includes single-piece test switch/charge indicator accessory. UL Listed for factory or field installation, Certified to CA Title 20, and registered in the California Modernized Appliance Efficiency Database (MAEDBS) as a small battery charger.