Brand new 5V relay module; Can be as SCM development board, or home appliance control; 5~12V TTL control signal; Control DC / AC signal, or 220V AC load; With one normally open and normally close point; With power indicator; With control indicator; Adds relay coil on transistor drive to control pin impedance; IR transmitter can convert power energy to invisiable light; Widely used in various photoelectric switch and remote transmitting circuit