The Helios FDS 450 Purlin Box is specifically designed for mounting RD series roof fans and ventilation hoods on flat roofs with inclines up to 25°. Constructed from corrosion-resistant GRP, the unit features abrasion-resistant insulation that provides both thermal and acoustic benefits. It ensures a reliable, snow-proof base height and includes all necessary installation accessories such as fastening screws, profile rubber, and sealing for a secure fit between the base and the fan. This mounting solution offers long-lasting durability and efficient performance in all weather conditions, making it ideal for professional rooftop ventilation systems.