Hey @stevenandbecky. Are the window sensors wired or wireless? If they are wired, you can use the Ring Retrofit Kit to allow you to still get the benefit of these sensors that are already installed, and allow you to be professionally monitored on those sensors from the Retrofit kit. If they are wireless, you will be unable to add them to the Base Station, as they are most likely not Z-Wave (only frequency the device can communicate on to be added to the Base Station) and need to be Ring Alarm Contact Sensors to be added and professionally monitored.