residential, commercial and industrial applications, the Hold-open function ease usage because the powering of the strike and the opening of the strike do not need to be exactly synchronized. 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 alternating current (AC) to the strike instead of direct current (DC). When using a DC powered strike, a buzzer accessory can be added to create the buzzing noise, if desired. There are many manufacturers of electric strikes, and there are many things that have to be considered when buying one, i.e., type of jamb, type of locking hardware, whether one requires fail-secure, fail-safe or hold-open function, length of the latch, depth of jamb, voltage requirements and the length of the faceplate. In some cases, it is a good option to choose a magnetic lock. Before using a magnetic lock, the Fire Marshal or appropriate authority should be consulted. There are emergency egress issues that must be addressed before using a magnetic lock. Types of electric strikes by locking device Electric strikes can be differentiated in a number of ways, frame type it can be installed in, duty (continuous or intermittent), and which variety of locking mechanism on the door it can work with. The four most common locking mechanisms concerned with electric strikes are Cylindrical, Deadbolt, Mortise, and Rim Panic Exit Devices. Cylindrical electric strikes are generally the cheapest due to their use in residential markets. Deadbolts, also known as deadlocks, do not have a spring mechanism which generally means the strike for a deadbolt is 'hold' only (the deadbolt is thrown and it engages in the electric strike cavity, the electric strike can release it but cannot subsequently 'recapture it' since the deadbolt lacks the spring latching capability of the other lock sets). There are specialty electric strikes that hold the electric strike keeper open until the door with the extended deadbolt closes back into the electric strike to "recapture" the extended deadbolt. Mortise type locksets tend towards larger projecting latches from the door to engage deeper in the frame and electric strikes used for these locking mechanisms require more cutting and space in the frame. Rim exit devices (panic bars or crash bars) are required in many buildings as a 'single motion' means of egress and electric strikes used in these