Easy to Install and Use: Motion sensor doorbell, no wiring is required, easy to use. Support recording, with 16 beautiful songs. Useful and Effective: The motion sensor can detect movement within 4-5 meters, you will know anyone entering your setting area. Convenient and Safety: Motion sensor door chime doesn't only bring convenience but also safety and guest salutation. Wide Applications: Alarm door bell is suitable for home, offices, business shops, stores, hotels, factories, doorway entrance or any place requiring either guest saluting function, alarm or motion detection. Battery Powered: The device can be used by 3x AA batteries (Batteries Not Included) to make it work. Specification: Material: Plastic, Electronic Components Color: White Battery: 3 x AA batteries (Not Included) Size Chart: Size: 91x61x28mm or 3.58x2.40x1.10inch Package Includes: 1 Piece Doorbell Note: 1. Please allow slightly error due to manual measurement. 2. Due to the difference between different monitors, the picture may not reflect the actual color of the item. 3. Wish you a wonderful on-line shopping! Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Sold by-YJL official store