Feature: 1. Advanced Integrated Design: The module body of this product contains for ESP32 WROVER B and other modules, which innovatively integrates WiFi, Bluetooth, and GSM GPRS functions, eliminating the need to purchase multiple devices for network access and data transmission, and allowing you to have a full range of network connectivity with a single investment. 2. Powerful Battery Management: The module is equipped with a lithium battery charging and discharging circuit and can work normally while charging the battery, avoiding interruptions caused by low battery power during use. And this function also provides over‑charging and over discharging protecting, fully guaranteeing the service life and safety of the device. 3. Diversified Communicating Methods: Equipped with a SIM card slot compatible with mobile, Unicom 2G 3G 4G nanoSIM card, in addition to WiFi, Bluetooth transmission, you can also utilize the SIM card to provide voice, SMS, data and other communicating functions, not only the function of the ordinary module, but also for emergency situations to provide more options. 4. Humanized Interaction Interface: The product is designed with microphone input and sound output ports, users can not only interact with the device through data transmission, but also utilize the sound interface to achieve voice control and feedback, which brings a more comfortable and efficient use experience. 5. Easy to Debug and Operate: The Type C interface is extended by the USB to serial chip CP210x, which can be directly connected to a computer with a USB cable for debugging and data transmission. An onboard IO 13pin blue LED indicator makes the device status clear at a glance, so even beginners who are not familiar with hardware operation can easily get started. Specification: Item Type: Wireless WiFi Bluetooth Development Board Material: PCB Supply Voltage: DC 3.6‑5V (TypeC Port 5V Input) SIM Card Type: NanoSIM Card (not Included) Network System: GSM, GPRS 850/900/1800/1900MHz Functions: Support WIFI and Bluetooth Transmission Support Voice, SMS and Data Message Transmission Two Sound Ports On Board: Including Microphone Input and Sound Output Port One IO 13pin Indicator Blue LED On Board. Package List: 1 x Development Board2 x Pins1 x Aerial1 x Adapter1 x Instruction Manual