Nora Lighting NX-615-LED/R2F Self-Diagnostic Die-Cast Aluminium LED Exit Sign with Battery Back-up Letter Colour Red Two SidesNORA Lighting NX 615 LED R2F NX 615 LED R2F Product Description For architectural applications, Nora Lighting offers its low profile, die cast aluminum LED exit sign with battery backup. Both die cast faces are brushed to give a simple, yet elegant, effect. In the event of power loss, the LED light sources will remain illuminated at their full light level for 90 minutes. Self Diagnostic feature automatically tests to ensure proper operation.