3V Relay Board For Raspberry Pi Arduino Relay Module 1 Channel Opto-Isolate High Level Trigger For Iot Esp8266 Microcontrollers Development BoardSpecification: channel: 1 channel Material: circuit board control signal: TTL Work voltage: Dc 3V33V Main chip: EL817, SRD-Dc03V-SL-c compatible Load:10A 250VAc, 10A 30VDc Response time :Less than 20 mil..