Check the listing for details. LED Exit Sign (2-pack) Battery Backup UL Ceiling Mount / Wall Mount. Condition: New. Listed at 31.49 USD. 2 exit signs. DESCRIPTION- Fully assembled single face exit with extra face plate for easy eld conversion to double face- Housing snaps together with no additional mechanical fasteners- Universal mounting- Easy installation- Universal snap in and out chevron design meets all local and state codes- High grade slim injection molded, V-O ame resistant, high impact thermo-plastic housing with snap-t design components for easy installation.- White or Black housing with ” red or green letters- Automatic solid state charger- Solid state short circuit overload protection- Self Diagnostic / Self-Testing function (option SD) is available- OPERATIONThe exit sign is continuously illuminated by normal AC power. Whenever normal AC power fails, the internal solid statetransfer switch automatically connects internal battery to the LED lamps inside the exit sign to keep it continuously lit for90 minutes. When AC power is restored, the battery is recharged by the onboard solid state recharger and is accomplishedwithin 12 hours.