This Non-Foil-Face FlexWrap is not UL Listed for use with chimney liners, but it is great when you need only small pieces for stuffing into nooks and crannies.

Non-Foil-Face FlexWrap can also seal the space between an insert shroud and the fireplace facing, or between frames of glass doors and the fireplace facing.

Seals the space between an insert shroud and the fireplace facing, or between frames of glass doors and the fireplace facing.