There are two versions of the GEMC-12V2APS: GEMC-12V2APS-CF (Commercial Fire) contains a transformer mounted inside the housing that requires a direct connection to a dedicated 120VAC circuit. The GEMC-12V2APS-R (Residential Fire/Burglary, Commercial Burglary) uses a plug-in 16.5VAC, 50VA class 2 transformer. Both versions use the GEMC12V2ABOARD UL Listed Subassembly. The GEMC12V2APS-CF or GEMC-12V2APS-R can be used as either: A UL Listed Accessory to a Gemini C-Series Combination Fire & Burglary Alarm control panel and GEMINI series control panels (GEM-X255, GEMP9600, GEM-P3200, Freedom F-64, GEM-P1664, GEM-P1632 and GEM-P816) or A UL Listed power supply for use with any listed Fire Alarm Control Panel (FACP), burglary control panel or access control system requiring an additional 12VDC auxiliary power Both versions use the GEMC-12V2ABOARD UL Listed subassembly, suitable for use as a replacement board.