A panic exit device is a device that allows users to open a door by pushing a bar or a touchpad. It is also known as a crash bar, a panic bar, or a push bar. It is designed to provide fast and easy exit in an emergency situation, such as a fire or a crowd crash. It is often required by building codes and fire regulations for public buildings, such as schools, hospitals, or hotels. They can also prevent unauthorized entry from the outside by locking the door when closed. They come in different styles and sizes to fit various types of doors.