Because the electric lock provides the physical barrier to a secured area, the level of security is determined by the choice of electric hardware. Fail-safe locks are used on doors that are in the path of a fire exit; they are also called continuous-duty devices. A fail-secure lock requires power to unlock it. The development of electronic locking hardware has focused on security, access control, and life safety. The locks most commonly used as part of an access control system include the magnetic lock, electric strike, electric lockset, and electric dead bolt. When choosing a lock device, the designer must consider code requirements, operation and traffic flow, door and frame construction, preexisting door hardware, aesthetics, the interface with the access control system, power requirements, security requirements, and the budget. 3 figures