This wireless door chime has a working range up to 500 ft, and comes with 50 unique chimes and 4 volume levels. Easy to install by plugging the receiver into any standard outlet and sticking the sensors to your door or window. It also has a reminder function for open doors or windows, and is expandable by adding more receivers and sensors. Features 1. Excellent Working Range: Our wireless door chime working range up to to 500 ft. Far enough to cover every door and window in your house. 2. 50 Music with 4 Volume Levels: Our door entry alert has 4 levels of adjustable volume. 50 unique chimes allow your wireless door and window entry alert system to meet any need. 3. Easy Installation: Plug the receiver into any standard outlet. Tear the double-sided tape and stick the sensors to the door or window. The receiver will alert immediately when the sensors separated. 4. Reminder Function: If your door or window is left open. The receiver will ring every 5 minutes, auto-silence after 5 times. You can turn off this function if you don't need it. 5. Expandable Wireless Door Chime: You can add more receivers and sensors in multiple areas. Each wireless doorbell receiver can pair up to 50 sensors and each sensor can add unlimited receivers. Specification Material: Plastic Color: White Size: 8 x 8 cm Weight: 80 g Plug Type: US, UK, EU Package Include: 1x Wireless Door Chime