Fangrui Product Details And Stable Esp-12f Wifi Module On Board, Large Capacity 4mbyte Flash. I / O Port And Uart Program Download Port Of Wifi Module Are All Led Out To Facilitate Secondary Development. The Power Supply Mode Supports Dc12 V. Reset Button And A Programmable Button For The Onboard Wifi Module. Esp-12f Supports The Use Of Eclipse / For Lde And Other Development Tools, And Provides Reference Programs Under For Development Environment. On Board 16 Channel 24 V / 10 A Relay, Output Switch Signal, Suitable For Controlling The Load Whose Working Voltage Is Within Ac 250 V / Dc 30 V. On Board Power Indicator, Relay Indicator And One Module With Led. Two On-board Shift Registers 74hc595 Control The Relay Switch. The 16 Way Relay Is Controlled By Two 74hc595 Cascades, So The Corresponding Control Program Of 595 Is Needed To Open And Close The Relay. The Reference Program Has Been Provided. Burning And Writing Port: Gnd, Rx, Tx And 3.3v Of Esp8266 Are Respectively Connected With Gnd, Tx, Rx And 3.3v Of External Ttl Ser Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.