We carry both the Silicone and the Neoprene high temp ducting. The Silicone has a max heat temp of 600F, they are sold in 11 foot sections. The Neoprene is rated up to 350F and sold in 10 foot sections. They are designed for moving air from a wide temp range, they are lightweight and extremely flexible. Both are made with fiberglass cord and bronze plated steel spring wire helix. The sizes range from 1” to 6” some with 1/2” increments available. Lowest prices in the country.