Guilford of Maine Sona Acoustical Fabric, Fire Rated, 60 inches Wide in Warm Grey Color An ATS Acoustics Exclusive made by Guilford of Maine, the best-known maker of acoustical fabrics 14.4 oz. weight per linear yard, 17 x 15 construction (thread count per inch) Flammability: ASTM E84 Class I or A. Designed specifically for acoustical applications, this is a slightly lower thread count version of Guilford FR701 fabric. Sold by the yard. One yard is 60" wide by 36" long