Currently unavailable.
Fire stop size: 7”/180mm or 8″/200mm (for 5″ & 6″ inside diameter twin wall flues)
The Firestop is used internally where the flue run passes through a slabbed or joisted area. The Firestop is designed to allow for the 50mm required clearance between the flue and combustibles.
https://laoisstone.ie/product/....fire-stop-plate-blac