OBEX CORTEX 0220FR Class A1 Breather Membrane features water resistant yet breathable technology, which facilitates the escape of moisture and the prevention of condensation within the external wall construction. It can be applied to many surfaces including sheathing board, concrete and insulation. This Breather Membrane achieves A1 fire-classification when tested to EN 13859-2, the highest fire classification available. The membrane is installed using the OBEX CORTEX 0825 Installation Kit which includes 2 rolls of 0824FR Double-Sided Tape and 6 rolls of single sided 0823FR UV Façade Tape. Typical Uses In façade construction behind cladding systems, ensuring water does not penetrate into the structure. Behind external masonry or curtain walling, to safeguard the primary waterproofing from wind-driven rain and to allow moisture from inside to escape.