If you are wanting to add listen-in ability to your M1 series control you'll need these. These are microphones that will allow those who are at a remote location to listen in to activity at the panels location. Twelve of these can be connected into an M1TWI or a M1EZ8TWI.
Specifications:• Operating Voltage: Powered from M1TWI or M1EZ8TWI
• Current Draw. 5mA each
• Circuit Board Dimensions: 1.5" x 1"