The ESP-07S is a small form factor Wi-Fi module with an onboard antenna, created by the Chinese electronics manufacturer Ai-Thinker. It is based on the ESP-07 Wi-Fi transceiver and ESP8266 microcontroller. It is compliant with 802.11b/g/n Wi-Fi standards and operates in both 2.4GHz and 5GHz spectrum. The ESP-07S is designed for low-power applications, consuming only around 20mA of current in transmission and sleep modes, and only 30µA of power when in deep sleep mode. It is also RoHS compliant, featuring an operating voltage of 3.3V-3.6V, and supports UART communication protocols for easy integration into embedded systems. The ESP-07S has a detachable, U.FL connector antenna which allows for greater flexibility in antenna selection for the user. Additionally, the module also contains 4MB of flash memory.