Wireless Intercom System for Home & Office. White color. 4 devices total. 5300 Ft Range Real Time Two-Way Communication Group Call Full Duplex (4 Pack): 3 of the devices are NIB. 1 device is in great used condition- however, is missing the USB-to-Micro USB cable & brick charger. Can connect to any Micro USB cable. Easy to set up Compatible with Smartphone Features mute option