Here at US Fireplace Products we carry a wide variety of chimney liners. If you need a custom square or rectangular liner we now have BestFlex Heavy-Flex Liner available. In addition to over 130 sizes we can also get just about any component that you will need for your job. Just contact us and let us know what you need. Or check out page 9 of our Lindemann Catalog.
Best-Flex Heavy-Flex is availalbe in 304 stainless steel for woodburning and 316 stainless steel for all fuels. It carries a transferrable Lifetime Warranty.