The module uses authentic quality relay, normally open interfaces, Maximum load: AC 250V / 10A, DC 30V / 10A;Use SMD isolation optocoupler, ability to drive, stable performance.Trip 5mA current.The operating voltage of the module 5V; The module can be high or low by a trigger of the jumper setting.The fault-tolerant design, even if the line is case sensitive, the relay 't work;The power indicator (green), the flag of the State of the relay (red)Interface module:1. DC: positive supply (VCC)2. DC: power negative (GND)3. IN: control relay may be high or low levelRelay outputs:1. NO: normally open relay interface2. COM: Common interface relays3. NC: normally closed relay interfaceHigh and low level triggering options:It is low level trigger when the jumper connects to bottom pinIt is high level trigger when the jumper connects a high pinPackage contents: 1 x 1-channel level Relay module optocoupler shutter buttonFour hole mounting bolts, 3.1mm diametersize:50mm x 26mm x 18.5mm (L x W x H)Material:PCBcolour:BluePackage Contents:1 x Relay ModuleOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.