This intercom adopts high performance electro-acoustic circuit technology the output power up to 3W anti-interference and noise reduction makes voice clear and loud Inside and outside have separate speaker and microphone microphone volume and sensitivity can be adjusted separately Two-way communication window intercom identification and automatic processing of audio signals no need to press any button easy to operate and convenient to use The microphone line outside is 187cm more convenient and easy to install and use Microphone not only transmit sounds clearly the height also could be adjusted according to your needs Sturdy and durable with thick metal panel scratch resistance applicable to banks at order points at the counters at toll stations at bus stations to keep a safe social distance