1pcs 5V 1-Channel Relay Module with Optocoupler H/L Level Triger for Arduino Module description: 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 Operating voltage 5V; 4. the module can be high or low by a jumper setting trigger; 5. fault-tolerant design, even if the control line is broken, the relay will not operate; 6. the power indicator (green), the relay status indicator (red) 7. the interface design of human nature, all interfaces are available through a direct connection terminal leads, very convenient 8. module size: 50mm*26mm*18.5mm (L*W*H) Module interface: 1. DC+: positive power supply (VCC) 2. DC-: negative power supply (GND) 3. IN: can be high or low level control relay Relay outputs: 1. NO: normally open relay interface 2. COM: Common Interface Relays 3. NC: normally closed relay interface High and low level trigger options: It is low level trigger when jumper connect to LOW pin It is high level trigger when jumper connect to HIGH pin