Most state laws require apartment buildings to have its common entry doors operated by an electric strike. This helps protect the occupants there-in. What is an electric strike – An electric strike is an access control device used for doors. Electric strikes are sometimes equipped with buzzers that allow someone outside the door to hear when the door is open. The buzzing noise is typically made by applying current (AC) to the strike. How is the lock controlled – The lock can be controlled by card access, phone, fire alarm unlocks, or by a door attendant. What types of frames can the electric strike be installed in – The most common frames that the electric strike is installed in are: aluminum, hollow metal doors and frames.