1. Powerful function: T-Call V1.4 ESP32 wireless communication module with FPC antenna and SIM card is both ESP32 WROVER-B and module, providing comprehensive features and functions. 2. Easy to use: The peripheral device adopts CP210X USB-to-serial port chip, which can be easily connected to a computer or device through USB to achieve fast and stable data transmission. 3. Integrated design: This module integrates ESP32 WROVER-B and modules into a compact package, so that users can enjoy the advantages of these two modules on one platform. 4. Battery powered option: The module has a lithium battery charging and discharging circuit and overcharging and overdischarging protection, it can be powered by the battery and at the same time, with high portability and convenience. 5. Wide compatibility: The module supports low-power voice, SMS and data transmission, which is very suitable for applications. Power supply voltage: DC3.6V~5V (TYPEC port 5V input) Onboard lithium battery interface and integrated lithium battery charging and discharging circuit Module can work while charging the battery Charging current 500MA Support WiFi and Bluetooth compatible transmission Flip SIM card slot design, can use China Mobile or 's 2G/3G/4G NANO SIM card Support voice, SMS, data information transmission Two onboard audio ports: including microphone-in and audio-out ports Onboard 1 IO13 pin indicator blue LED Colour:black Material:plastic Size:7.5 x 3 x 1cm Package Contents: 1 x Bluetooth module board(set) Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.