Feature 1DOORBELL UNIT: The pack contains 2 pcs doorbell system units, which can switch between ringtone call and intercom mode. 2INTERCOMUNICADOR FUNCTION: the two units can be used as intercomunicador for two way talk without shouting at home. 3LONG RANGE: The transmission distance of the voice intercom device can achieve 1000m in open area and 20 to 50m through wall, highly practical. 4INDICATOR LIGHT: The voice intercom units are designed with intercom light and power light, users can see clearly at a glance. 5LONG BATTERY LIFE: The 2 way voice intercom has built in battery, adopts intelligent power saving chip, with long battery life.Item Type: 2WayVoiceIntercomMaterial: ABSModel: H8Battery: Rechargeable Lithium Battery 3.7V 2000mAh (Built in)Use: Widely used in household, office, laboratory environment, medical treatment, etc.Basic Parameter:Working Temperature: -20 to 55Transmission Distance: 1000m in open area, 20 to 50m through wall Operating Frequency: 410M to 490M .wang-edit-text{ font-family:'Arial' important; } .wang-edit-text table { b-top: 1px solid 000; b-left: 1px solid 000; } .wang-edit-text table td, .wang-edit-text table th { b-bottom: 1px solid 000; b-right: 1px solid 000; padding: 3px 5px; } .wang-edit-text table th { text-align: center; }Package List2 x 2 Way Voice Intercom2 x Base2 x USB Cable1 x User Manual