Fangrui Product Details 1. On-board And Stable Esp-12f Wifi Module, Large 4m Byte Flash Capacity. 2. The Wifi Module Input / Output Port And Uart Program Download Port Are All Led Out To Facilitate Secondary Development; 3. Reset Button Of Built-in Wifi Module. 4. Esp-12f Is Compatible With Development Tools Such As Eclipse / Ide. 5. 2 To 5v Relays, Output Switch Signal, Suitable For Controlling Ac Working Voltage Charge Within 250v / Dc30v. Integrated Power Indicator, 1 Programmable Led And Relay Indicator. Colour: Green Material: Pcb Size: 78x47mm Package Contents: 1 X Esp8266 Esp-12f Wifi Relay Module Only The Above Package Content, Other Products Are Not Included. Note: Light And Different Displays May Cause The Color Of The Item In The Picture A Little Different From The Real Thing. The Measurement Allowed Error Is +/- 1-3cm.