Everbilt 4 in. x 12 ft. R6 Insulated Flexible Duct Silver Jacket
Everbilt 4 in. x 12 ft. R6 Insulated Flexible Duct Silver Jacket. Th EVERBILT 4 in. The duct has R6 insulation which contains 33% more insulation than the standard R4. 2 product. The product is also covered in a heavy duty, silver jacket for durability.