The Helios RVK 500 is a robust cover designed for both supply and extract air openings, offering tight, spring-loaded sealing. It is fully compatible with reversible fans and built from durable, impact-resistant light grey plastic. The integrated stainless steel spring ensures a secure closure. The number of louvres included depends on the unit’s size. This model supports a maximum air velocity of 6 m/s for supply air and 8 m/s for extract air, making it suitable for a variety of ventilation setups.