The Helios M 2 is a control and protection unit designed for two-speed three-phase fans equipped with thermal contacts. Housed in a durable, light grey plastic enclosure rated to IP55, it is ideal for surface-mounted installations in industrial or commercial settings. The unit features a 3‑stage selector switch (0−1−2) for controlling fan speed and includes an indicator light for operational status. In the event of a fault, the fan must be manually restarted by switching to the 0 position, ensuring safe and controlled operation.