Brivo ACS6100 Regular Expansion Chassis (Accommodates four (4) ACS6100 expansion boards) Includes: Regular enclosure with lock B-ACS6100-PSB internal power supply board (does not support power for electronic locks) Plug-in AC/DC power adapter 12v 14Ah sealed lead acid battery backup (Compatible with all Brivo ACS6000/6100 series boards) *The B-ACS6100-PSB Can be used to replace an ACS6000 series power supply board.