Used wherever a Ceiling Support, Finish Support, or Fire Stop is installed below an open attic. The Insulation shield is required to guard against the hazard of blown-in or blanket insulation filling any framed opening or contacting the chimney and possible storage of combustibles against the chimney. Adaptable design usable for new and retrofit installations. Half cylinder passes easily through ceiling openings between 16" O.C. joists. Part can be removed with-out cutting if attic is converted to habitable space and chimney is fully enclosed. Readily trimmed for reduced height installation close to eaves. Base of unit is 16” sq.