Tisan ESP8266EX Chip Development Module Board Set  Description:  Power Pin:   5V from USB 5V power supply. 3V3 provided by a 3.3V regulator chip board. GND Ground pin.     MCU:       Master encapsulates ESP8266EX chip.   Support 80MHz clock speed and 160MHz.   ESP8266EX built SRAM memory、 due to the need to load the basic firmware、 the  remaining SRAM space is about 50KB.   Here is the main board schematic:Here is the bottom board schematic:Package included:1 x Tisan ESP8266EX Chip Development Module Board Set