1、High accuracy relay module is very durable, easy to use in the practical life. 2、Trigger mode is low pulse trigger and self-locking relay module is entitled with high performance according to strict rule. 3、With strong stability, relay board's installation is simple, which not require particularly complicated operations. 4、Built to strict quality control standards, 4-channel relay is improved for more durability. 5、After many inspections before leaving the factory, relay module's quality is guaranteed, you can use it with confidence. Item Type: Relay module Model: SL25A04 Working Current: 1 relay pull-in 70MA, 2 relay pull-in 140MA, 3 relay pull-in 210MA, 4 relay pull-in 280MA Static Working Current: 0.4mA Trigger Mode: Low level trigger Pin Description: V: Positive power supply G: Negative terminal of power supply and ground terminal of trigger signal; T (T1 / T2 / T3 / T4): Trigger signal input (0.2-2 second low pulse). NO: Relay normally open port COM: Relay common port NC: Relay normally closed port Instructions: At power-on, the relay opens. Click the trigger port (T1 / T2 / T3 / T4 port) relay to pull in (and hold), then click the relay again to disconnect, and so on. 1 x Relay Module