SELKIRK CORP 104100 Gas Vent Tee, 4-Inch Manufactured in United states Easy to use Highly durable 4" inch, 4RV-TS, Round, Type B, Gas Vent Tee RV series offers round gas vent pipe and fittings for residential commercial and industrial applications Features a snap together, non-positional lock system, die formed ends and eliminates the need for all cutting, fitting and special engineering Has an improved joint design which provides for a secure connection in seconds Constructed with a galvanized steel outer casing and an aluminum inner liner