ROCKWOOL COMFORTBATT is a semi-rigid stone wool batt insulation for exterior wood and steel stud applications in both new construction and renovations. It features a unique flexible edge designed to compress as the batt is inserted then spring back, expanding the batt against the frame studs to give a complete fill. This flexibility ensures the expected R-value is achieved and maintained.Non-combustible and fire resistant, COMFORTBATT will not develop toxic smoke or promote flame spread, even when exposed directly to a fire. It is also offers water and moisture resistance and excellent sound absorbency.COMFORTBATT is an effective way to improve a home's energy efficiency. It is GREENGUARD Gold Certified and contributes to a healthier indoor environment.