The GSC3500 Series allows offices, schools, hospitals, apartments and more to build powerful voice intercom solutions that expand security and communication. These devices offer 1 and 2-way voice functionality with HD speakers and multi-directional microphones with a 4.2 meter voice pickup distance. The GSC3500 Series supports a wide-range of peripherals including Bluetooth devices, offers built-in whitelists, blacklists and greylists to easily block unwanted calls, provides integrated dual-band Wi-Fi and includes advanced acoustic echo cancellation.