Description Double wall stove pipe is a connector pipe that links wood stoves to insulated chimneys. This system fatures a black aluminized steel outer casing and heavy gauge stainless steel inner liner. 1/4" Air space between inner and outer pipes provides superior insulating value. 6" Clearance to combustibles. For installed length subtract 1-3/8" per joint. Listed to ULC S641 And UL 103 Standards.