1. Hands-Free Two-Way Communication: Enjoy seamless, real-time communication with Hand Free Two Way Wireless Doorbell design, just like using a phone. The convenient hands-free feature frees you from holding a button, allowing relaxed conversations. 2. Effortless Usage: Once connected, there's no need to hold the intercom button continuously. Experience freedom and ease as this Intercom System Doorbell lets you roam and talk without interruption. 3. Portable Mobility: With its design, this Apartment Room Intercom offers mobility and flexibility, making it easy to move around and call from locations in your space. 4. Impressive Wireless Range: The system supports up to 500 meters outdoors and 400 meters indoors, penetrating three walls effortlessly. Stay connected with Wireless Voice Duplex Intercom Doorbell technology for reliable communication. 5. Build and Smart Features: Constructed with ABS material featuring a matte finish for touch. The exterior is equipped with rain protection. The intelligent design includes voice prompts for low battery alerts ensuring timely recharging. Wireless Voice Duplex Intercom Doorbell 500M Hand Free Two Way Wireless Doorbell with Rechargeable Battery Intercom System Doorbell for House Home Factory Office Power supply: polymer battery Battery capacity: 1000mAh for both internal and external units Battery power supply: DC5V/1A Working temperature: -20 degrees to 60 degrees Music ringtones: 4 songs 8 levels of adjustable volume Product size: 146.00x94.00x54.00mm/5.75x3.7x2.13inch (internal unit), 104 x 55 x 31mm (external unit) Color: Black Material: plastic 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.