Volume: high, medium and low, 3 levels of volume adjustment Ringtones: 6 ringtones Built-in battery: 800 mAh indoors, 800 mAh outdoors Call distance: up to 500 meters in open areas outdoors Call: 1 to 10, answering can only be one-to-one USB interface: Type-C/DC5V-1A Installation method: wireless installation, simple and convenient Use scenarios: home, restaurant, villa, company, courtyard, etc. Colour:black Material:ABS Package Contents: 1 * Doorbell 1 * Receiver Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm. 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!