Features: 1. RINGING UNIT: The package includes 2 door bell system units, which can switch between ringtones and intercom mode. 2. INTERCOM FUNCTION: Both units can be used as an intercom for two-way conversation without shouting at home. 3. LONG RANGE: Voice intercom transmission distance can reach 1000m in open area and 20-50m through the wall, very practical. 4. INDICATOR LIGHT: The voice intercom units are humanized and designed with intercom indicator light and power indicator light, users can see clearly at a glance. 5. LONG BATTERY LIFE: Two-way voice intercom has a built-in large-capacity battery, adopts intelligent power-saving chip, with long battery life. Specifications: Item Type: Two-way Voice Intercom Material: ABS Model: H8 Battery: 3.7V 2000mAh rechargeable lithium battery (built-in) Usage: Widely used in home, office, laboratory, medical treatment, etc. Basic Parameter: Operating Temperature: -20℃ to 55℃ Transmission Distance: 1000m in open area, 20 to 50m through the wall Operating Frequency: 410M to 490M How to Use: Install and power on to use. Package List: 2 x Two-way Voice Intercom 2 x Base 2 x USB Cable 1 x User Manual