Damaged?: Unknown Flexible duct products are performance-tested in accordance with industry standards to ensure reliability and years of service. Our core is tested (in accordance with ADC FD 72-R1) for actual installation static pressure / temperature performance. Polyester cores are also tested for microbial resistance by GEI per ASTM D6329-98. Vapor barriers are tested for permeation in accordance with ASTM test methods.. Color: Silver. Insulated: Yes. Insulation R-Value: 8. Insulator material: Other. Material: Fiberglass. Maximum air flow (CFM): 3141. Pack Size: 1. Certifications and Listings: UL Certified. Product Depth (in.): 300 in. Product Diameter (in.): 12 in. Product Height (in.): 17 in. Product Length (in.): 300 in. Product Width (in.): 17 in. Wall Thickness (in.): 2.5. Maximum air flow (CFM): 3141. Insulated: Yes. Product Diameter (in.): 12 in.