Flashing color: This product has 7 flashing colors, which can be adjusted according to personal preferences and specific occasions to add decorative effects to the doorbell.Music selection: Built-in multiple music options, users can adjust according to their preferences to create a warm family atmosphere.Wireless design: No complicated wiring is required, the doorbell adopts a wireless design, which is convenient and fast, and no tedious installation steps are required. Suitable for the elderly and the hearing-impaired: The doorbell has a loud volume and is equipped with a light flashing function. The elderly and the hearing-impaired can directly notice the sound and light effects of the doorbell, which is very convenient.Practicality: In addition to being used as a doorbell, this product can also be used as a server for young and elderly people with special needs to call family members or caregivers by pressing a button.Without dry cell batteries: Working voltage: DC4, 5V (3 batteries) Working current: less than 200mA Coding method: power supply Songs: 28 lines Volume: 0dB~85dB [8 levels adjustable)Receiving distance: more than 100M Size: Button 8*5*2.2cm/Part 10.2*6, 7*3.0cm Note: 1. Please allow 1-3 mm error due to manual measurement and 1-3g weight error make sure you don't mind before ordering. 2. Due to the lighting of the photos and the difference of monitors, the pictures may not reflect the actual color of the real item. Please make sure you don't mind before ordering, thank you! About Shipping: 1.please pay attention to your delivery address such as: name, street, house number, doorbell/email without name, etc. is correct, or the order will not be delivered correctly. 2.All items will be shipped within 3 business days after the payment is received. Most times you will receive them within 8-12 days then. The specific delivery time is depend on circumstances. 3.During the shopping process, if you have any questions, please feel free to consult us, we will reply you within 24 hours Hope you have a pleasant shopping experience!