4-inch multi-touch screen with 480 800 resolution; Optimal HD audio, full duplex technology; Yealink Noise Proof Technology; Built-in rechargeable lithium battery; Up to 20 hours talk time (in ideal conditions); Up to 75 hours standby time in Wi-Fi mode (in ideal conditions); 20-foot (6-meter) and 360 degree voice pickup; Built-in 6-microphone array for voice pickup; 5-way conference call; Hybrid UC meeting; Built-in Wi-Fi (2.4GHz/5GHz, 802.11a/b/g/n); Built-in Bluetooth 4.2.