This is D1 mini, it is a mini NodeMcu Lua WiFi board based on ESP-8266EX. D1 Mini NodeMcu Lua 4M Bytes WLAN WiFi Internet Development Board Base on ESP8266 ESP-12F for Arduino, 100% Compatible with WeMos D1 Mini 11 digital input / output pins, all pins with interrupt / PWM / I2C / support 1 line (except D0); 1 analog input(3.2V max input). Micro USB connection; Compatible with Arduino; 1MB Flash; 500mA resettable fuse. WIFI development board,4M bytes.5V 1A switching power supply (switching power supply?onboard. Our D1 mini development board compatible with Arduino WeMos and can be programmed in the for Arduino IDE.