The DuraVent W2-WT8 wall thimble is a reliable fitting for your vent system. It belongs to the FasNSeal, a collection of special gas vent and gas vent connectors. This wall thimble has an inner diameter of 8 inches with a length of 18 inches. It is made of the AL29-4C, a special type of stainless steel that is extremely resistant to corrosion and cracking, assuring you of its durability over the years. This is used for through-the-wall termination and it fits between standard wall studs. It also accommodates wall thickness of 5 to 11 inches. With an adjustable vent length included, it allows for adjustability in the length variance.This DuraVent W2-WT8 is UL listed and is covered with a limited lifetime warranty.DuraVent is committed in providing their customers high quality and innovative products for their venting system. Search for more of their products at affordable prices only here at PlumbersStock.com.