Description: 【Wireless Calling】: This intercom doorbell is wireless, making it easy to install and use. It's great for the elderly or those with mobility issues who may need to call family members or caregivers at any time, from anywhere 【2 Way Voice Communication】: The caller and receiver can engage in 2 way voice communication, ensuring smooth and conversations. The transmission distance is approximately 1000 meters in open areas 【Adjustable Volume】: The volume of the doorbell can be adjusted according to your needs, ensuring that calls be heard clearly even in noisy environments 【Long Distance Transmission】: With strong signal penetrating, this device can transmit signals over hundreds of meters in open areas, ensuring timely receipt of calls across different rooms or floors 【Emergency Assistance】: The caller comes with an emergency button for the elderly to press during emergencies, allowing them to quickly call for help when needed Specification: Material: Plastic Size Chart: Outdoor Use: 12.1cmx6.16cmx1.8cm/4.76inchx2.43inchx0.71inch Indoor Use: 11.6cmx7cmx1.8cm/4.57inchx2.76inchx0.71inch Package Includes: 1 set 2 Way Intercom Doorbell Note: Please allow slightly errors due to manual measurement and different monitors.