Update your heating and cooling with quality components, like the DuraVent 5VFT-35BL Ventinox VFT Black Single-Wall, 5" x 35'. Don't hesitate to contact us if you aren't sure this is the part you need. Used for upgrading or restoring masonry chimneys that vent Category I natural gas, propane or oil appliances, wood or pellet stoves, fireplaces and fireplace inserts. Single-wall, .006” 316 Ti (Titanium) stainless steel. Continuous weld delivers a strong, air and water tight flue gas conduit.