Features: It consists of the keyes ESP32-IO expansion board and the keyes ESP32 board. When used, only DC7-12V voltage needs to be input on the black head, and then it can power the keyes ESP32 board. The expansion board also comes with a dialing switcher for controlling the power switcher. Developers can connect peripheral devices as needed. When using the development board for development and debugging, standard headers on both sides can make your operations easier. The ESP-WROOM-32 module is an industry-leading integrated WiH+Bluetooth-compatible solution with less than 10 external components, integrating antenna switches, RF balance imbalance converters, power amplifiers, converters, low noise amplifiers, filters, and power management modules. At the same time, it also integrates TSMC's low-power 40nm technology, power performances and RF performances, making it safe and easy to expand to various applications. Specifications: Material: PCB Size:Approx.6.7x5cm/2.63x1.96inch Option Type:1pc ESP32 Board,2pc ESP32 Board,5pc ESP32 Board; Microcontroller: ESP-WROOM-32 module USB to serial chip: CP2102-GMR Power supply voltage: DC7-12V Working current: 60mA Most power: 0.3W Operating temperature: -25°C to+65°C WiFi modes: Station/SoftAP/SoftAP+Station/P2P WiFi frequency: 2.4GHz~2.5GHz Bluetooth-compatible protocol: compliant with Bluetooth-compatible V4.2BR/EDR and BLE standards Package Includes: Package A 1pc ESP32 Board Package B 2pc ESP32 Board Package C 5pc ESP32 Board note: Please allow 1mm errors due to manual measurement. Due to the differences between different monitors, the picture may not reflect the actual item color.