SFC - Single-wall Flexible Gas Vent Connector. Single-wall flexible construction. Includes an integral appliance draft hood connector for fast installation. Locks onto Hart & Cooley Type B gas vent. Requires only 1" clearance to combustibles per installation instructions. UL-listed for use as a connection from an appliance to Type B gas vent in conditioned spaces only. Do not enclose. Available in 3" through 5" diameters and 1' through 5' lengths.