Feature: 1. [Long Range]: This wireless intercom doorbell boasts a tested communicaterange of up to 1000m/3280ft, making it suitable for large homes, hotels, villas, factories, and hospitals. It ensures clear communicate from the 1st to the 8th floor, providing convenience and security for your property. The doorbell also comes with a user friendly design, including intercom light and battery light indicators for easy operation. 2. [Easy Installation and Use]: With no need for wiring or internet connection, this wireless telephone intercom doorbell is easy to install and use. It features a slim design with a thickness of only 18mm, providing a comfortable hand feel. The doorbell also features a high gloss UV surface for a premium feel and durability. 3. [Customizable Ringtones and Volume]: Choose from 38 different ringtones to suit your personal preference. The doorbell also allows for 3 volume adjustment for both ringtones and call volume, ensuring that you never miss a visitor. 4. [Long Battery Life]: Both the outdoor and indoor units are powered by 1800mAh rechargeable batteries. The outdoor unit can work for about 8 months with normal use (5 presses per day, 2 minutes per call), while the indoor unit can work for about 3 days and can be continuously charged on its charging base. When there are two indoor units, press the ringtone button and the other indoor unit rings the ringtone. Press the TALK button to directly talk to each other. 5. [Sturdy and Weather Resistant]: The outdoor unit of the intercom doorbell is rated IP54 for water resistant and comes with a rain cover, allowing it to be safely installed outdoors. The indoor unit, however, is not water resistant and should be kept indoors. Specification: Power Supply Method: Rechargeable battery Working Temperature: -20 ° C to 55 ° C Transmission Distance: About 1000m/3280ft of open space, 20-50m/66-164ft of partition walls Working Frequency: B-gear frequency 462MHz, A-gear frequency 434MHz Working Hours: Charging the outdoor unit once takes about 8 months, while charging the indoor unit once takes about 3 days Charging Time: Approximately 5 hours when fully charged Music Ringtones: 38 ringtones Volume: 3 adjustment (standby machine volume adjustment key) Call Sound: 3 adjust call size (adjust volume key during call operation) Outdoor Unit Water Resistant Grade: IP54 Indoor Unit Water Resistant Grade: None Battery Capacity: 3.7V/1800mAh Product Colors: Black Product Quantity: 1 Outdoor Unit with 2 Indoor Units Outdoor and Indoor Unit Hosts Size: 116 * 56 * 18mm/4.6 * 2.2 * 0.8inch Water Resistant Cover Size: 121.5 * 61.5 * 31.3mm/4.8 * 2.4 * 1.3inch Charging Dock Size: 70 * 56 * 29mm/2.8 * 2.2 * 1.1inch . Package List: 1 * Outdoor Unit 2 * Indoor Unit 1 * Instructions 1 * Screwdriver 1 * USB Data Cable 1 * Wall Tape