1, outlined
The functional role:
1. When the door would not close very strongly, increased comfort, but also more elegant door closing action.
2. The door is not fully closed will increase the risk, with this feature you will not have to worry about.
2, electric door pull works
Electric door pull: also known as magnetic pull of the door. The main gate is controlled by the power-off closure. Magnetic force generated by energizing the door is closed. De-energized, the magnetic force disappears, the door opened. On the door frame (or the door panel edge) equipped with an electromagnetic coil, when the door is opened, the current through the coil will, so as to form an electromagnetic field so that the magnetic force, when the door is closed from the door frame to close the door will be automatically suction.