CONTINUOUS SOUND ABSORBING PERFORATIONS FOR A MONOLITHIC APPEARANCE Product Details: Perforation: 6mm / 18mm o.c. Panel Thickness: 1/2″, 12.5mm Non-Woven Fabric: Charcoal Gray Open Rate: 8.7% NRC: Up to .85 Board Sizes: 900 mm x 2700 mm 1200 mm x 2000 mm Product Data Sheet: Sonus Round 6/18