SpecSeal® Composite Sheet is a high‑performance firestop solution ideal for sealing large openings that require a durable, permanent barrier. Constructed from a thin galvanized steel sheet bonded to a high‑expansion intumescent layer on one side, the Composite Sheet delivers robust protection against the spread of fire, smoke, and heat. Engineered for versatility, SpecSeal Composite Sheet partners seamlessly with other SpecSeal firestop products—including Firestop Collars, Wrap Strips, and EZ Path® Devices—to effectively reduce oversized or irregular openings and restore code‑compliant firestopping. Its rigid yet workable design allows for easy cutting, fitting, and installation on mechanical, electrical, and mixed‑use penetrations. The result is a reliable, permanent firestop solution ideal for commercial, industrial, and high‑security environments requiring long‑term fire and smoke containment.