Double doors are everywhere—office buildings, hospitals, schools, and hotels. They offer wide passage and a sense of grandeur. But there's a hidden component working behind the scenes to keep these doors functioning safely and effectively: the door coordinator.

Picture a busy commercial building during an emergency evacuation. People rush toward the exits, pushing through double doors in their haste to escape. Behind them, both door leaves swing shut—but not in the right order. The active leaf closes first, its latch bolt projecting into the frame and blocking the inactive leaf from closing properly. A gap remains. Smoke begins to seep through.