Feature:1. [Wireless Intercom System] This doorbell intercom kit includes three units, two indoor and one outdoor, allowing for switching between ringtone call and intercom mode.2. [Indicator Lights] Humanized design with intercom and power indicator lights, this wireless intercom doorbell provides clear visual cues for users.3. [Long Range] The transfer distance of this intercom system can achieve up to 1000 meters in open area, and 20 to 50 meters through wall, offering strong practicality.4. [Adjustable Function] Portable intercom system with 2 channels A and B, and 3 volume levels, allowing users to customize settings according to their preferences.5. [Wide Applications] This clear sound intercom system is suitable for various scenarios such as hospitals, hotels, factories, and teahouses.Specification:Item Type: Wireless Intercom DoorbellMaterial: ABSWaterproof Rating: IP54Battery: 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 55Transfer Distance: Open Field: 1000mThrough Wall: 20-50mOperating Frequency: 410MHz to 490MHz.Package List:2 x Indoor Units1 x Outdoor Unit2 x Bases2 x Data Cables1 x DC Power Cord1 x User Manual1 x Sticker1 x Screwdriver