ESP8266 ESP-12E WiFi Shield for Arduino UNO

Shield Pin interface compatible with standard spacing Arduino Uno. 3.3V power supply chip (power chip CC3000). Onboard ESP8266-12 WiFi module come with an enhanced PCB antenna. On board DIP switch ESP8266-12 provide module operation mode. Integrated serial port chip with built-in 5V to 3.3V TTL level converter.
The onboard four LED displays the status of ESP8266, namely PWR, DFU, AP, STA.

Reference

• Arduino UNO + ESP8266 ESP-12E UART WIFI Shield