High Performance : This product is a 1 channel flip-flop latch relay, and low pulse trigger module. Typical applications:Automotive electronics,industrial equipment,engine, LED,smart home, emergency lighting,MCU development board, toy car. Adopted of high quality electronic components, and precision process, ensure for the durability. This is a bistable (self-locking) relay module that triggers once the relay pulls (and holds); Trigger again, relay release (and hold). USE : 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.