UL Classified 5/8″ Type X gypsum board inserted in the cavity between the two layers. Warnock Hersey has approved the Safeguard Cabinets to be mounted in any face of fire rated steel or wood stud for up to 2 hour rated walls without affecting its fire rating. The above meets the requirement test ASTM-E119-98 with test report WHI-495-1534. MOUNTING INSTRUCTIONS are supplied with each safeguard cabinet.