Feature: 1. 1500M ULTRA LONG CALL DISTANCE: Voice intercom doorbell adopt a professional walkie talkie chip. In a flat and open place, the theoretical call distance can reach 1500M, making your contact more convenient 2. EXCELLENT WALL PENETRATION: Wireless voice intercom doorbell use 462MHz radio frequency for wider signal coverage and easier wall penetration 3. CLEAR SOUND QUALITY: Wireless voice doorbell use core noise reduction technology, intelligent noise reduction to make your calls clearer 4. 3 LEVELS OF VOLUME ADJUSTABLE: The elderly can also hear, the highest volume of 2 way talk doorbell is not less than 112 decibels, whether in the bedroom or in the kitchen can be heard 5. DURABLE BATTERY LIFE: 1 way talk doorbell internal and external machines are built with 2000mAh rechargeable lithium battery, lasting life is no problem 6. STRONG INTERFERENCE RESISTANT ABILITY: Voice intercom doorbell has 3 individual channels to choose from, easy to avoid interfering wireless frequencies. The internal machine can talk to each other, fast and convenient, support smooth communication 7. WIDE APPLICABLE SCENARIO: Wireless voice 1 way talk doorbell is suitable for home, villa, company, teahouse, office, home and other areas Specification: Item Type: Voice Intercom Doorbell Power: 0.5W Channels: A, B, C 3 Channels Number of Connections: A maximum of 3 sets of non string numbers, unlimited connections under the same channel number Battery: 1 x 2000mAh rechargeable lithium battery. Package List: 1 x Internal Machine1 x USB Cable1 x Charging Base