Use this 8 Zone Hardwired Expansion Module to add 8 hardwired zones to your 8-Zone Security Panel and Cabinet or Power 864 Security System (each sold separately). They can be located in the main panel, in an expansion case, or under any keypad when used with the 7505B2 backplate. The 8 Zone Expansion Module adds 8 hardwired general purpose burglary or fire zones provides 100mA @ 12VDC auxiliary current. It connects to the alarm panel via the 4 wire COMM bus, which is the same wire that the Keypads and other devices are connected to. This means that these devices do not need to be in the same box as the alarm panel.