Microcontroller: ESP8266EX
Operating Voltage: 3.3V
Digital I/O Pins: 11 (all I/O pins have interrupt/PWM/I2C/one-wire capability, except for D0)
Analog Input Pins: 1
Flash Memory: 4MB
6. On-Board Switching Power Supply:
Input Voltage Range: 9V to 12V
Output: 5V at 1A Max