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. From the Manufacturer 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.