SL300 Series is the Hearth & Home Technologies chimney system for wood-burning fireplaces with an 8" flue. The SL3FL96 is a 4 x 8 foot flat sheet of flashing for SL300 Series chimneys, intended to be cut and formed on site for a custom roof penetration seal. Use it where a standard pre-formed roof flashing does not fit the roof pitch or material. Always confirm the pipe size, approved components and clearances in your fireplace, stove or chimney installation manual before ordering. Special order.