Each piece of Selkirk"s Heat Fab Saf-T Liner is constructed of seam-welded 24 Gauge stainless steel, This 304 Alloy version carries a lifetime workmanship and materials warranty for wood burning applications, Saf-T Liner comes pre-drilled with pop rivets included, for insulation use Heat Fab Saf-T Wrap - aluminum-jacketed sections of ceramic blanket that snap and lock around your pipe, Heat Fab Saf-T Liner is UL listed to the 1777 Standard where 1"" of clearance from chimney exterior combustibles is present when Saf-T Wrap Insulation is used, Heat Fab 24"", Saf-T Liner for 6"" Pipe, Constructed of seam welded 24 Gauge stainless steel, Comes pre-drilled with pop rivets included, UL Listed to 1777 Standard with 1"" clearance with Saf-T Wrap, SKU: CPPF5359