The Multiboard eXBound 15mm – S-Edge is an external magnesium-oxide (MgO) high performance external boundary wall cladding system. The square edges to all sides of the sheets allow for the application of expressed-edge cladding. With the provision of external fire-mastic at the joints, a single layer application of this system achieves a FRL 90/90/90 for fire, and meets the BCA requirements for acoustic performance.