Fireproof insulation is 100% gypsum, reinforced by a 1" by 2" lattice made of 14-gauge galvanized welded steel wire. Field replaceable steel panels can be easily replaced. Finish is an environmentally friendly, scratch-resistant electrostatic powder coating applied to all sides, including bottom. Drawer bodies are built with high sides for use with hanging folders. Drawer locks on all files provide general locking of all drawers through either standard key locks or UL-listed high-security locks. Drawer pulls are surface mounted to allow for extra insulation inside the drawer heads. Insulation between all drawers makes each drawer a separate insulated container. 2-position drawer catch allows access to certain drawers while others remain locked. Drawer heads are formed of welded steel and filled with fireproof gypsum insulation and are field replaceable.