Features: The compatible board can directly connect to this module. It is widely used in networking, smart home project when it is connected to the WiFi router. With the help of ESP-01 adapter module, it can be connected directly with the 5V MCU development board.　 It is TTL serial communication interface and its parameters can be set by AT command. Support three modes: for AP, for STA, for AP+for STA coexistence mode Compatible with 5V/3.3V, and powerful internal LWIP protocol Specification: Interface logic voltage: 3.3V / 5V compatible(On-board level shift circuit) Working voltage: 4.5V - 5.5V (On-board 3.3v LDO Regulator) Working current:0- 240mA Module size: 4.2*2.5cm/1.7*1in Adapter size: 2.5*1.5cm/1*0.6in Weight: Approx.8g/0.3oz Package list: 1 x Wi-Fi Wireless Module 1 x Adapter 1、The compatible board can directly connect to this module. 2、It is widely used in networking, smart home project when it is connected to the WiFi router. 3、With the help of ESP-01 adapter module, it can be connected directly with the 5V MCU development board. 4、Support three modes: for AP, for STA, for AP+for STA coexistence mode 5、Compatible with 5V/3.3V, and powerful internal LWIP protocol