4-Way Intercom Audio Doorphone Loudly Clear Voice Doorbell Kit Easy to Install -RL-0004

■ Multi-user intercom 4-way kit. Build-in microcomputer-controlled circuit and coding and decoding digital circuit. Only 4 cables for connecting all the units with stable performance and anti-interference function. ■ Intercommunication is available between indoor phones with privacy kept. ■ Busy line reminding and ring-off indicating ■ Centralized power supply. ■ Clear voice. ■ Maximum talking distance: 300m. ■ 4-wire connection. ■ Enclosed an adapter.