This is plug-in doorbell intercom is great for your peace of mind. Not only offers convenience when answering your door, but safety for you and your family. Easy to install.  If you have a doorbell, you can use your existing doorbell wiring and  no new wires are needed for this intercom system.  The interior intercom module plugs into any electrical outlet and communicates with the intercom doorBox via the existing electrical power line in your home. This plug-in doorbell intercom is expandable up to 4 stations. This kit comes with a doorbell module and one 3-channel power line indoor intercom module.
SPECIFICATIONS:
Door Module:
· Power Source 12VAC @60 Hz.
· Choice of two carrier frequencies (A) 230 KHz, (B) 260 KHz.
· RF output 80 mW (70 mW - 100 mW).
· Standby current 30mA.
· Maximum current 180 mA.
· Dimensions 3 in x 5.25 in x 1.25 in
3-Channel Wireless Intercom:
· Power source 110VAC @ 60 Hz.
· Carrier frequency (A) 230KHz,(B) 260 KHz,(C) 290 KHz
· RF output power 100mW.
· Audio output 500mW.
· Modulation method - Frequency Modulation (FM).
· Dimensions 6"x5"x1"
Manufacturer: Westinghouse
Manufacturer warranty: 1 year limited
Product questions: 800-842-5378