Any opinions on Ecovent?

[JChurch]

I’m shopping around for a Class A chimney kit and came across Ecovent which offers a kit at a significant savings. Has anyone ever used their product and can provide feedback about the quality?

Upon contacting customer service, I was informed that their double wall class A kit is not compatible with double wall black stove pipe. Is this unusual? Is there a work around or adapter to get double wall stove pipe to connect?

Here is the kit.

(broken link removed)

Thanks for any help you can provide!