Based on this product's specifications, here are some alternatives and similar models
Rack accessory Rittal 3244.810 — built-in fan, 1 fan, airflow 770 m³/h, plastic housing, grey
Summary description:
Rittal 3244.810 is a rack-mounted accessory featuring a single built-in fan with an airflow of 770 m³/h. The unit has a plastic housing in grey and is supplied as one piece per pack. Designed to provide forced ventilation for cabinets and enclosures, it helps maintain temperature control and improve equipment reliability in server racks, network cabinets and electrical enclosures.