A bedroom door is the natural boundary between ordinary domestic life and whatever classified operation happens to be on the other side. Unfortunately, younger brothers, older sisters, and curious parents have historically shown little respect for handwritten warnings taped at eye level.
This doorknob-mounted alarm adds a little more security to the perimeter. Hang it from the knob, switch it on, and after a brief arming delay it stands watch for movement at the door. If someone tries to enter, the alarm sounds loudly enough to announce that a security breach has not gone unnoticed.
The flexible cable fits a variety of doorknobs, and the setup is simple enough for junior agents to use whenever headquarters needs protecting.
