The Kangaroo Siren + Keypad is the base station for your security system. With it, you can manually arm and disarm your Kangaroo security system. If one of your Kangaroo sensors is triggered, the siren will sound, scaring off intruders and alerting neighbors. The Siren + Keypad is designed to work in conjunction with a Kangaroo sensor. It can be controlled by your Kangaroo Tag or using the app.