1、[Wireless Intercom System] This doorbell system kit includes 3 units, 2 outdoor units and 1 indoor unit, allowing for seamless switching between ringtone call and intercom modes. 2、[User Friendly Design] The intercom unit features indicator lights for intercom and power, providing users with clear visual cues for easy operation. 3、[Long Range] With a transfer range of up to 1000 meters in open area and 20 to 50 meters through wall, this wireless intercom system offers practicality and convenience. 4、[Adjustable Settings] The portable intercom system comes with 2 channels (A and B) and 3 volume levels, allowing users to customize settings to suit their preferences. 5、[Versatile Application] This doorbell intercom system with clear sound is suitable for various settings including hospitals, hotels, factories, teahouses, and more. Item Type: Wireless Voice Intercom Doorbell Material: ABS Waterproof Rating: IP54 Battery: Indoor Unit: Rechargeable lithium battery 3.7V 1800mAh (built in) Outdoor Unit: Rechargeable lithium battery 3.7V 1800mAh (built in) Use: Widely used in household, office, laboratory environment, medicine facility, etc. Basic Parameters: Working Temperature: -20℃ to 55℃ Transfer Distance: Open Field: 1000m Through Wall: 20-50m Operating Frequency: 410MHz to 490MHz 1 x Indoor Unit 2 x Outdoor Unit 1 x Base 1 x Instruction Manual 1 x Data Cable 2 x Power Cord 1 x Sticker 1 x Screwdriver