3HR BATTERY BACK-UP - Can be wired in either maintained or non-maintained mode, allowing function as part of a regular lighting circuit or only when the power is lost. When the mains supply is lost, the unit will operate for a minimum of 3 hours, providing a clear, illuminated exit route guidance during evacuation. VERSATILE OPERATION - For convenience to the installer, this LED bulkhead can be used in Maintained or Non-Maintained operation. LEGEND KIT INCLUDED - For ease of use a legend kit with Up, Down, Left & Right arrows is included in with the kit. REPLACEMENT FOR T5 BULKHEAD - This LED light is a direct replacement and energy efficient alternative to traditional T5 style emergency bulkheads. Non-maintained emergency lighting is designed to turn on in the event of a power failure. It is linked into the building's lighting circuitry and reacts to a power failure ensuring emergency exit routes remain illuminated.