5 Type B Gas Vent Hi-Wind Top Termination from the RV Collection Part of the chimney system roof assembly the hi-wind top is designed with a dome to exclude rain and leaves and a side wall to improve flue gas flow and prevent downdrafts. It is used in high wind environments. The RV series offers round gas vent pipe and fittings for residential commercial and industrial applications. It features a snap together non-positional lock system die formed ends and eliminates the need for all cutting fitting and special engineering. It has an improved joint design provides for a rapid and secure connection in seconds. The use of our LockTab feature gives installers the option of engaging this tab instead of using sheet metal screws when required by local code. Features: Residential and light commercial and industrial Materials: Galvanized steel outer and aluminum inner liner Easy to use LockTab or non-positional lock system Fuel: Gas UL 441 listed Minimum Safety Clearance to Combustibles: 1 for diameters of 3 to 24 2 for diameters 26 to 48 Warranty: Lifetime Limited Warranty