It leads to a WiFi module power supply or service interface to facilitate developers to extend the power supply and maintenance. This is a development board for the ESP8266 module from Expressif Systems It is an excellent way to interface or develop for the popular ESP8266 modules It can be used with NodeMCU Lua or Micropython to run scripts AT command firmware can be installed to control the device via serial commands, or it can be programmed with your own Sketch or firmware directly from the Arduino IDE Specifications: Material :Metal Specifications: It leads to a WiFi module power supply or service interface to facilitate developers to extend the power supply and maintenance. This is a development board for the ESP8266 module from Expressif Systems It is an excellent way to interface or develop for the popular ESP8266 modules It can be used with NodeMCU Lua or Micropython to run scripts 100 percent brand and high quality Package Included: 1 x Piece Development Board Notes: Due to the difference between different monitors, the pictures may not reflect the actual color of the item. Compare the detail sizes with yours, please allow 1-3cm error, due to manual measurement. Please leaving a message before you give the bad feedback,if the products have some problems. Thanks for your understandings.