This Doorbell Notification package from Bellman & Symfon is part of the Visit Smart Home System that helps you to keep tabs on your home. This package includes a Door Transmitter, Pager Receiver, Charger, and Bed Shaker. Those alerting devices in this package are already paired as a system and ready to use out of the box. Just place the Door Transmitter close to your existing door chime and when someone rings your doorbell, you will be alerted with colored LEDs and vibrations from the Pager Receiver. The Pager Receiver is powered by a single battery so you can easily carry it as you walk around in your home and still get the alerts. During the night, by putting the Pager Receiver into the Charger and attaching the Bed Shaker, you will be alerted with strong vibrations from the bed shaker which will wake up even the heavy sleepers. This package is a great signaling system to help people with hearing loss, hard of hearing, and deaf not to miss any visitors.