Specification: _x005f_x000D_ Power supply voltage: DC 3.6V~5V (TypeC 5V input) _x005f_x000D_ On board lithium battery interface and integrated lithium battery charging and discharging circuit _x005f_x000D_ Charging current: 500MA _x005f_x000D_ WIFI: 802.11 b/g/n (802.11n, speed up to 150 Mbps), frequency range 2.4 GHz to 2.5 GHz _x005f_x000D_ Bluetooth-Compatible: Complies with Bluetooth-Compatible v4.2 BR/EDR and BLE standards _x005f_x000D_ On board power indicator light red LED; _x005f_x000D_ One IO19 pin indicator light green LED on board _x005f_x000D_ On board battery charging indicator light blue LED _x005f_x000D_ Product size: about 39 * 31 * 6mm/1.53 * 1.22 * 0.23inch _x005f_x000D_ Product weight: 15g _x005f_x000D_ _x005f_x000D_ _x005f_x000D_ Note: _x005f_x000D_ Due to the different monitor and light effect, the actual color of the item might be slightly different from the color showed on the pictures. Thank you! _x005f_x000D_ Please allow 1-2cm measuring deviation due to manual measurement. _x005f_x000D_ _x005f_x000D_ _x005f_x000D_ Included: _x005f_x000D_ 1 x Development Board 1. High-Performance Module: Features the ESP32-WROVER-B module, which integrates Wi-Fi, Bluetooth-Compatible, and BLE capabilities for high-performing wireless connectivity. 2. Easy-to-Use Design: Comes with a USB to serial chip (CP2104) and Micro USB interface for easy connection to a computer for debugging. 3. Built-in Battery Circuit: Equipped with a lithium battery charging and discharging circuit, allowing for battery-powered operation or charging. 4. Wide Compatibility: Supports DC 3.6V~5V input voltage and features 802.11 b/g/n Wi-Fi and Bluetooth-Compatible v4.2 BR/EDR and BLE standards for wide compatibility.