Core Features: High-performance SIP cordless phone system 1.8? 128 x 160 TFT color screen with intuitive user interface Ruggedized DECT handset with IP54 protection rating Up to 20 simultaneous calls Up to 10 DECT cordless handsets Up to 10 SIP accounts Support Opus audio codec Noise Reduction System FNR (Flexible Noise Reduction)/Noise Cancellation Up to 40-hour talk time Up to 575-hour standby time Quick charge: 10-minute charging time for 2-hour talk timeTLS and SRTP security encryption Vibration alarm guarantees Wall mountable charger Up to 10 DECT cordless handsets and 10 SIP accounts Up to 20 simultaneous calls to ensure that each handset can make two calls Maximum DECT radio coverage: 50 meters indoors 300 meters outdoors Energy-saving ECO features.