The Alarm Door is a medium-sized, sturdy metal door with a rectangular shape and a slightly weathered surface, featuring visible scratches and dents from frequent use. It has a prominent alarm system integrated into its frame, including a blinking red light and a small speaker grille, suggesting its function to alert when breached. The door's edges are reinforced with thick metal bands, and it sports a matte finish with a combination of dark gray and muted red colors for a utilitarian yet ominous look.