High-performance SIP cordless phone system 2.4? 240 x 320 TFT color screen with intuitive user interface Up to 20 simultaneous calls to ensure that each handset can make two calls Up to 10 DECT cordless handsets and 10 SIP accounts TLS and SRTP security encryption Flexible Noise Reduction (FNR)/Noise Cancellation Up to 21-hour talk time (in ideal conditions) - Up to 166-hour standby time (in ideal conditions) Quick charge: 10-minute charge time for 2-hour talk time Headset connection via Bluetooth or 3.5 mm jack Maximum DECT radio coverage: 50 meters indoors, 300 meters outdoors