4″ x 25′ Flexible Semi-Rigid Aluminum Duct – Item #334
Semi-rigid aluminum duct is ideal for applications where building codes require use of all aluminum duct. The duct is totally non-combustible with a maximum operating temperature of 400°F.
- Continuous airtight lock-seam
- Class 0
(1) – 4″ x 25′ Flexible Semi-Rigid Aluminum Duct