Right now there are 186 deals from Amazon Resale, formerly Amazon Warehouse Deals, in Tools & Home Improvement › Building Supplies › HVAC › Ducting. These are inspected returns and open-box items that Amazon sells and ships itself. WarehouseHunter puts each one next to its current new price, so you can see what you save at a glance.

Brands with the most offers here: VIVOSUN, PATIKIL, Hon&Guan, CAP, AC Infinity, DuraVent, Degree, Kohler. Every item is a one-off, so the stock moves all day and new deals keep arriving.