This little beauty is the D1 mini based on the WeMos design powered by an ESP8266-EX.

Sporting a USB (CH340) connecting it to your computer (yes - you might need to install the CH340 drivers) makes it a breeze to connect and WeMos libraries available on Arduino IDE make them easy to program.

SPECIFICATION

• ESP8266-EX Microcontroller
  
• Voltage: 3.3V
• Analogue Input Pin: 1 (max input 3.2V)
• Digital Pin: 11
• Clock Speed: 80Mhz/160Mhz
• Flash: 4MB 

IN THE PACK

• ESP-12/D1 Module
• 2x Short Female Headers
• 2x Long Female Headers
• 2x Short Male Headers