Williams Furnace 9A335 High Altitude Conversion Kit for 3509821 and 3509621A w57.9 Manufacturiers* Brand Type Diameter American btu50000 Manufacturiers* Brand Type Diameter American Metal HS AC Triple Wall 6" (15 cm) American Metal HSS AC Triple Wall 6" (15 cm) DuraVent DuraTech 1" Solid Pack 6" (15 cm) DuraVent DuraTech Canada (DTC) 1" Solid Pack 6" (15 cm) DuraVent DuraPlus HTC 2" Solid Pack 6" (15 cm) DuraVent DuraTech Premium 2" Solid Pack 6" (15 cm) DuraVent DuraPlus AC Triple Wall 6" (15 cm) Metal Fab Temp Guard 1" Solid Pack 6" (15 cm) Olympia Chimney Champion Chimney System 1" Solid Pack 6" (15 cm) Olympia Chimney Rockford Chimney Systems 1" Solid Pack 6" (15 cm) Olympia Chimney SBI Venting Division Ventis 1" Solid Pack 6" (15 cm) SBI Venting Division Nexvent 1" Solid Pack 6" (15 cm) Security Chimney S 2100+ 2" Solid Pack 6" (15 cm) Selkirk CF Sentinel (CF) 2" Solid Pack 6" (15 cm) Selkirk Super Pro 2100 (ALT) 2" Solid Pack 6" (15 cm) Selkirk Super Vent 2100 (JM) 2" Solid Pack 6" (15 cm) * Specific components may be required depending on the chimney manufacturer Rutland 610 & 611 Safety Data Sheet an AMEX listed company whose notoriety brought new levels of prestige to the firm Replacement Parts lists and exploded view diagram