Metalbest RV 4" x 7" Type B Gas Vent Low Profile Double Wall Increaser

4" x 7" Type B Gas Vent Low Profile Double Wall Increaser from the RV Collection This gas vent increaser allows you to adapt 4" diameter pipe to 7" diameter pipe when required for your application. 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 Ad...