12V 8-Channel Relay Module Optocoupler Low Level Triger for Arduino Precise Features 1.Using high-current relay, AC250V 10A DC30V 10A 2.Contact some independent wiring, safe and reliable 3.Standard interface, can be extended in a variety of development board 4.With fixed screw holes for easy installation 5.Suitable for a variety of platforms such as 51/AVR/AVR/ARM Module interface: 1, VCC: 5V power supply connected to the positive 2, GND: 5V power supply connected to the negative 3, IN1-IN8: trigger signal, active low Relay outputs: a 12-line interface, the interface can be directly connected to all leads, user-friendly 1, NO1 - NO8: normally open relay interfaces, relay before the vacant after the pull shorted with COM 2, COM1 - COM8 Relay Common Interface 3, NC1 - NC8: normally closed relay interface relay shorted with COM ago, after the pull-vacant.