... , stoves, wall, firedoor core, pipe protection... It is made of expanded vermiculite board. The expanded vermiculite is natural and harmlessness ... Material: Expanded vermiculite2 Working temp:1100degrees3 Advantage: Natural, environmental-protection orientated, no poison and no radioactivity Fireproof, damp-proof,anti ... :Any size can design as your need. evironmental protection vermiculite board