Check the listing for details. DSC IMPASSA Self-Contained 2-Way Wireless Security Alarm System No AC = Hardwire. Condition: Brand New. Listed at 15.82 USD. IMPASSA Self-Contained 2-Way Wireless Security System NO AC Adapter version, needs hardwiring to an AC power supply on installation SCW455AU Version 1.30 Supports 64 wireless zones and 16 wireless keys (without using a zone slot) Optional integrated HSPA (3G) cellular, internet or dual communicator Cellular signal strength read-out to optimize placement Built-in 2-way audio VOX and push-to-talk alarm communication via phone line and cellular 2-way is available only on IMPASSA 9057 Self-Contained Wireless Security Systemt 4 keypad 4 sirens 16 wireless keys Remote firmware upgrade via cellular/internet Easy wireless device enrollment process Template programming Full 32-character programmable labels Enlarged keypad buttons 5 programmable function keys Individual FAP keys 17 user access codes 500 event buffer False alarm reduction features (CP-01 Outdoor temperature display Label Library Comes with Battery - Unguaranteed battery might be aging User Manual IMPORTANT NOTE: Please make sure these units will work with your current system and accessories or in your country, we do not accept returns, and are sold as is No Power Supply Included, needs to be hardwired to an AC supply in the wall, see our other listing for one with a wall AC power cable