Selkirk 208490 Firestop/Joist Shield, 16 in W x 20-5/16 in H Dimensions, 8 in, Stainless Steel

Used wherever a ceiling support, finish support, firestop or joist shield is installed below an open attic. 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.