Wi-Fi Module – ESP-12E module similar to the ESP-12 module but with 6 extra GPIOs.
USB – micro USB port for power, programming and debugging
Headers – 2x 2.54mm 15-pin header with access to GPIOs, SPI, UART, ADC, and power pins
Misc – Reset and Flash buttons
Power – 5V via micro USB port
Dimensions – 49 x 24.5 x 13mm
This item is also available in good quality.