Introducing the M4, an all-in-one extension handset designed for both IP PBX and mobile voice services. Seamlessly roam between WLAN and LTE networks in VoIP mode. Powered by a quad-core SoC platform, the M4 integrates Wi-Fi 2.4/5G, keypad, LCD, codec, SIP stack, and more, ensuring over 7 days of standby time. With Android OS compatibility, it offers exceptional stability and expandability. Easily deploy the M4 via the Vogtec online DIY cloud system or standard auto provisioning. Key features include FoTA updates, TR069 management, a 2.4" color LCD, vibration alert, 1800mAh replaceable battery, ENC, SIP video intercom support, BT4.1 headset compatibility, IPx5 rating, and a 500-number phonebook with LDAP support.