This self-locking relay module adopts the 9.5mm black fence type connection terminal and the standard 30A terminal, which makes it stable and firm and ensures its quality. This relay switch module adopts the industry's top quality ultra-small optocoupler, which makes it have a strong anti-interference ability and a stable performance. The output capacity of this relay module is AC 250V / 30A, DC 30V / 30A or less, it can control DC or AC load up within 30A. The delay time range of this self-locking relay module is 0 seconds~100 minutes, and it can be adjusted, it would be a great electronic accessory for you. This self-locking relay module has the function of permanent memory mode when the power is off, so you could use it with confidence.