ADTRAN 1175044L2 Battery Backup System (Hinged) TOTAL ACCESS BATTERY BACKUP SYSTEM (WALLMOUNT) - HINGED STANDALONE BATTERY BACK-UP SYSTEM 48 VOLT ADTRAN DESIGNED BATTERY BACKUP UP TO EIGHT HOURS UPTIME DESIGNED FOR USE WITH TOTAL ACCESS 612 616 624 750 850 912 916 OR 924 MOUNTING BRACKETS AVAILABLE (1200626L2) FOR MOUNTING A TOTAL ACCESS 612 616 OR 624 TO THIS WALLMOUNT BATTERY BACKUP SYSTEM (1175044L2) REPLACEMENT BATTERIES AVAILABLE (PN: 1975044L1)