Protect your doors, windows, cabinets and more with SimpliSafe Entry Sensors. The Entry Sensor is designed with a tiny magnet to detect when one opens. When the magnet moves more than two inches away from the sensor, it sounds the alarm. If you have a 24/7 Professional Monitoring Plan, it alerts the monitoring center who will dispatch police fast if there's an emergency. You can even set up Secret Alerts that will send a discreet notification to your phone instead of sounding an alarm. That means SimpliSafe Entry Sensors are perfect for preventing break-ins and protecting the liquor cabinet.