Lambro Ind. 427 Smooth Aluminum Duct
4'' x 60'' smooth aluminum ducting, snap lock. Crimped on 1 end. Major city building codes require that any dryer ducting placed within a drywalled wall must be a minimum of 5' to eliminate seams, must be smooth in texture (no ribbing), and must be of steel or aluminum manufacture (no vinyl, mylar, or PVC) to eliminate lint fires.