The Helios Fans ZV is an overrun timer designed for installation in a junction box on a 35 mm profile rail. It offers an adjustable overrun period ranging from 4 to 15 minutes and includes a sliding switch with three selectable modes: off (0), continuous operation, and overrun mode. This timer is suitable for combined use with lighting and fans, allowing for flexible ventilation control. The unit is rated for a maximum current of 16 A, operates at 50/60 Hz, and has an IP20 protection rating, making it suitable for standard indoor electrical enclosures.