Flexible 4 Inch Aluminum vent hose - Corrosion Resistant, Lightweight, Durable HVAC/Plumbing pipe for HVAC Systems, Plumbing, HVAC Ductwork (4 in x 25 FT) is up for auction in Tools & Home Improvement. The current bid is $2.00, 89% below the $18.99 MSRP, in New/Like New condition. This auction has ended — similar items appear in live auctions regularly.