learning all kinds of things reading this forum. Like I have said before I am still planning my fireplace insert install, but I had never heard of the insulated liner, I knew about the uninsulated ones from the kits the big box stores sell with their stoves. It sures pays to do some research! Thanks to all on here for all the info. And I do know I'll be buying the insulated liner, seems it's one of most important part of the install !