Features:This product is a 4 channel flip-flop latch relay, and low pulse trigger module.Thisis a bistable (self-locking) relay module,Trigger once, the relay pull (and holds);Trigger again, the relay releases (and holds).USE 1:By default, the relay is release, press the trigger button, the relay pull, press again, the relay release, the third press, the relay pull, and so on. USE 2:By default, the relay is release, MCU output low-pulse(0.3-1seconds), the relay pull, low-pulse again, the relay release, the third low-pulse, the relay pull, and so on.Typical applications: Automotive electronics, Motor, LED, Smart Home, Emergency lighting, MCU development board, Toy car.Adopted of high quality electronic components, and precision process, ensure for the durability.Specification:Working voltage: DC 5VWorking current: 1 relay 70MA; 2 relay 140MA;3 relay 210MA;4 relay 280MAStandby current: 4UALoad current: AC 250V / 10A, DC 30V / 10ATrigger mode: Low pulse triggerSize: 6.5*4.3cm/2.6*1.7inWeight: Approx.53g/1.9ozModule interface:5V: positive power supply (VCC)G: negative power supply (GND)T1: Trigger port 1T2: Trigger port 2T3 : Trigger port 3T4: Trigger port 4Relay outputs:1. NO: normally open relay interface2. COM: Common Interface Relays3. NC: normally closed relay interfacePackage list:1 x Self-locking Relay Module