Premier Plenum Duct is a flexible, non-metallic, corrugated raceway used for effective interior cable and fiber optic management. Premier Plenum meets UL-(910) standards for the National Electrical Code, Article 770, and satisfies UL-2024 standards for low smoke and flame propagation. Premier Plenum is offered in 3/4", 1", 11/4", 11/2" and 2", with pre-installed pull tape for easy cable installation.