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 modeCompatible with 5V/3.3V, and powerful internal LWIP protocolSpecification: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- 240mAModule size: 4.2*2.5cm/1.7*1inAdapter size: 2.5*1.5cm/1*0.6inWeight: Approx.8g/0.3ozPackage list:1 x Wi-Fi Wireless Module1 x Adapter .