Communication: WIFI (ESP8266 module) Product Size: 45 * 28mm Product Color: As pictures Working Voltage: DC5V Material: metal Features: Onboard Module:ESP8266 WIFI Module,can connect 5 client at the same time on the mode of AP Working Method:Mobile phone equipped with Wifi module Mobile phone and wifi module equipped with one router,and control the relay by APP Onboard Relay:5V,10A/250V AC 10A/30V DC relay