DOOR CLOSER 502

 A door closer is a hydraulic device that is used to automatically close a door after it has been opened. Door closers are commonly used as a fire prevention measure, typically installed on fire doors, as well as helping to prevent draughts

Door closers are most commonly installed on bathroom doors, fire doors, and exit doors in commercial buildings. During a fire, any door that penetrates a firewall must be fire-rated. Fire doors need to be closed in case of fire to help prevent the spread of fire and smoke.