Well I came home today with a package in my driveway and it was my Chimney liner. Problem is I ordered Heavy flex 304L stainless and this stuff has all the characteristics of easy flex. It is light, Corrugated on the inner lining, firm but I could easily crush it with my hands. Heavy flex says it is stiff and you can run over it with a truck. Also says it is smooth on the inside. Says it is too stiff to do a 90 degree sharp turn. This stuff seems easily flexed. The tech on the phone seems convinced I have the right stuff and that I am just mistaken? What do you all think?