Schlage 650 Series key switches can only be activated by a key. Key switches are commonly used for: ADA opening to enable/disable auto operators, operating overhead doors and locking/ unlocking access control openings to sensitive areas. Schlage 650 Series key switches utilize an innovative magnetic spring design which allows installers to configure both clockwise and counterclockwise key turn direction as well as momentary or maintained action in seconds.Each opening in your facility presents unique challenges. That’s why Allegion offers a variety of system accessories that allow you to customize an opening to meet specific security and safety concerns. System accessories include a variety of devices that enable specific functionality whether in standalone applications or as part of networked access control systems. System accessories are commonly used in conjunction with wall mounted readers as part of a traditional hardwired access control system.