Amazon.com: NodeMCU ESP8266 Development Board with 0.96 Inch OLED Display, CH340 Driver, ESP-12E WiFi Wireless Module, and Micro USB Works Great for Arduino IDE/Micropython Programming (Pin Header Soldered) : Electronics
ESP8266 Pinout Reference: Which GPIO pins should you use? | Random Nerd Tutorials
ESP8266 – Knowing the NodeMCU GPIOs or Pinout - The Engineering Projects
ESP8266 NodeMCU (Arduino compiler) Pins. Now with WeMos D1 Mini! – www.holdentechnology.com