DuPont Tuff-R (ci) Insulation Board is a high-performance polyiso foam with dual reflective foil facers. Tuff-R (ci) is a non-structural, rigid board insulation consisting of a glass-fiber-infused, closed-cell polyisocyanurate foam core laminated between 1.0 mil smooth reflective aluminum facers on both sides. As a result, Tuff-R (ci) offers high, long term R-value providing continuous, durable insulation within the building envelope.