It is a timing relay module with high precision performance, stable and reliable Supports 2 modes, mon mode (one-time) and cycle mode, and you can simply change mode by adjusting the jumper There is a wide range of time that you can set, both in time and out of time are adjustable It is great for controlling alternating stroke or repetitive switching on and off for equipment and product burn-in testing Widely used on equipment for time operation, machine repetitive test circuit, fish tank intermittent pump, etc