1. Powerful function: T-Call V1.4 ESP32 wireless communication module with FPC antenna and SIM800L integrates ESP32 WROVER-B and SIM800L modules, providing comprehensive features and functions. 2. Easy to use: The peripheral device uses CP210X USB-to-serial port chip, enabling easy connection to a computer or device via USB for fast and stable data transmission. 3. Integrated design: This module combines ESP32 WROVER-B and SIM800L modules into a compact package, allowing users to utilize the capabilities of both modules on a single platform. 4. Battery powered option: The module includes a lithium battery charging and discharging circuit with overcharge and over-discharge protection, supporting battery power and charging simultaneously for high portability and convenience. 5. Wide compatibility: The module supports low-power voice, SMS, and data transmission, making it suitable for various applications. Power supply voltage: DC 3.6V–5V (5V input via Type-C port) Onboard lithium battery interface with integrated charging and discharging circuit Module can operate while charging the battery Charging current: 500mA Supports WiFi and Bluetooth communication Flip SIM card slot design compatible with 2G/3G/4G Nano SIM cards from major carriers Supports voice, SMS, and data transmission Two onboard audio ports: microphone-in and audio-out Onboard blue LED indicator on IO13 pin Color: black Material: plastic Size: 7.5 x 3 x 1 cm Package Contents: 1 x Bluetooth module board (set) Note: Light reflection and display differences may cause slight variations between the product color in images and actual color. Measurement error allowed is +/- 1–3 cm.