To add a cellular module to a Lyric Controller, you will start by putting the system into its mode for installing a cellular module.You will then expose the expansion slot on the side of the system and insert the cellular module. Finally, finish the process by closing the side of the Lyric. There are three main cellular modules that can be used with the Lyric Controller. We generally recommend using the Honeywell LYRICLTE-A LTE communicator for this application. The LYRICLTE-A utilizes top-of-the-line LTE speeds, and it provides cellular service from the AT&T LTE network. This is far and away the fastest and most advanced cellular communicator that is currently compatible with the Lyric Controller. Update: The Honeywell LYRICLTE-V with service from the Verizon LTE Network is also now available! Remember, the cellular service that you choose to use with your Lyric will have nothing to do with the cellular service you receive for your phone. It is advised that you choose the service that works best in your area, regardless of what you use for your phone. Also keep in mind that you will need to have an alarm monitoring plan that includes cellular connectivity in order to use any type of cellular communicator with your Lyric. Complete the following steps to install a cellular communicator in your Lyric Controller: 1. Enter cell installation mode. From the home screen of the Lyric, go to Security > Tools > enter master code (default is 1234) > Advanced > Install Cellular Module > Yes. The Lyric will display a list of steps on the screen, indicating that it is in its cellular module installation mode. 2. Remove the side cover. On the side of the Lyric, there is a cover that protects its cellular expansion slot from exposure. You must remove this side cover to access the cellular expansion slot. Facing the front screen of the Lyric, push up on the right side of the system where the silver portion meets the white portion of the panel. You should be able to easily move up the side cover and pull it off. This can be seen in the animation below: 3. Insert the cellular module. Insert the cellular module into the expansion slot on the side of the Lyric. You will slide it to the left, into the slot until it is securely in place. When doing this, the information stickers on the cellular module should be on the front, the silver part of the module (the antenna) should be on the bottom, and the connector should be on the left, facing the panel.The proper positioning of the cellular module is shown in the picture below: 4. Attach the side cover. Reattach the side cover of the Lyric, and make sure that it snaps into place. This will complete the installation process for the Lyric cellular module. Indicate on the Lyric screen that you have completed the cellular installation process. This will power up the cellular module and allow it to connect to the network. Please note that you will still need to contact your monitoring company to activate the communicator.