DuraVent Type B Gas Vent Wall Thimble - For Vent Pipes with a 3" Diameter - 3GVWT: A vent pipe with a 3" inner diameter is required for this unit. When a chimney system goes through a flammable wall, this wall thimble is required. It supports the chimney while also ensuring that combustibles are kept at a safe distance. This thimble fits DuraVent Type B gas pipes up to 3" in diameter and may be adjusted to fit 3.5" to 6" thick walls. A 25-year warranty is included with the purchase of this item. Type B gas vent pipes from DuraVent can be used to vent a wide range of natural gas-fueled appliances.

Provides required combustible clearance for through-wall venting For use with 3" Dura-Vent Type B Gas Vent pipes Adjusts to accommodate walls with 3.5" to 6" thickness 25-year warranty