Check the listing for details. 5V One 1 Channel Relay Module Board Shield with optocoupler High and Low Level. Condition: New. Listed at 7.22 USD. 1, The module uses genuine quality relay , normally open interfaces Maximum load : AC 250V/10A, DC 30V/10A; 2, Using SMD optocoupler isolation , driving ability , stable performance ; trigger current 5mA; 3,The module voltage is 5Vare available ; 4,The module can be set to high or low triggered by jumper ; 5,Fault-tolerant design , even if the control line is broken , the relay will not operate ; 6,The power indicator ( green ) , relay status indicator ( red ); 7,Interface design humane, all interfaces can be connected directly via terminal wiring leads , very convenient; 8,Module size : 50mm * 26mm * 18.5mm ( L * W * H ); 9,Has four mounting bolts holes , hole 3.1mm, 44.5mm * 20.5mm pitch. Two module interface : 1, DC +: Positive power supply ( voltage required by the relay , 5V ); 2, DC-: Negative power connection; 3, IN: Can be high or low level control relay. Relay outputs : 1, NO: Normally open relay interface, the relay before the vacant after the pull shorted with COM; 2, COM: Common Interface Relays; 3, NC: Normally closed relay interface relay shorted with COM ago , after the pull- vacant. High and low trigger selection ends : 1 short jumper with LOW LOW triggered when connected ; 2 When the jumper is high with high short trigger . Package Included: 1 x 5V Relay Module with Optocoupler