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A realtor lock box hanging on the doorknob of a house for sale A real-estate lock box is a padlock -shaped box that generally hangs around the doorknob of a house that is on the market . The device holds the keys to a house to allow communal access for all real estate agents , while continuing to keep them secure. [ 1 ]
A crash bar (also known as a panic exit device, panic bar, or bump bar) [1] [2] is a type of door opening mechanism which allows users to open a door by pushing a bar. While originally conceived as a way to prevent crowd crushing in an emergency, crash bars are now used as the primary door opening mechanism in many commercial buildings.
A quick demonstration of an electronic door lock. An electronic lock (or electric lock) is a locking device which operates by means of electric current. Electric locks are sometimes stand-alone with an electronic control assembly mounted directly to the lock.
A buzzer or beeper is an audio signaling device, [1] which may be mechanical, electromechanical, or piezoelectric (piezo for short). Typical uses of buzzers and beepers include alarm devices , timers , train and confirmation of user input such as a mouse click or keystroke.
A U.S. Marine performs a ballistic breach of a padlocked door using a combat shotgun. Door breaching is a process used by military, police, or emergency services to force open closed or locked doors. A wide range of methods are available depending on the door's opening direction (inward or outward), construction materials, etc., and one or more ...
An improved "shear" electromagnetic lock was patented on May 2, 1989, by Arthur, Richard and David Geringer of Security Door Controls, an access control hardware manufacturing firm. The device outlined in their designs was the same in principle as the modern magnetic lock consisting of an electromagnet and an armature plate.
A door phone controller (DAC-1Z) can be connected to your Merlin Plus system to allow employees to answer calls made from a business entrance. It is connected directly to a CO line port on the Merlin Plus control unit. Callers using the door phone can press a button at the building entrance to ring a telephone in your Merlin Plus system.
An electric buzzer uses a similar mechanism to an interrupter bell, but without the resonant bell. They are quieter than bells, but adequate for a warning tone over a small distance, such as across a desktop. A buzzer or beeper is an audio signalling device, which may be mechanical, electromechanical, or piezoelectric.