https://www.ebay.com/sch/i.html?_nkw=3M+Silver+Fire+Barrier+Composite+Sheet&_sacat=0&_dmd=2

3M Silver Fire Barrier Composite Sheet

Regular price
$269.00
Sale price
$188.00

Firestop Composite Sheet, Width 24 In, Length 36 In, Cable Trays, Cables, Ducts, Metal Pipe, Plastic Pipe, Up to 4 hr. Fire Rating, Silver, Fire Barrier Composite Sheet