door knocker

a metal object connected to the back of a door, which people hit against the door as a way of asking others to let them in

A door knocker is a decorative device attached to the front door of a home, used to announce a visitor's arrival. Typically made from materials like metal or wood, door knockers come in various designs, ranging from simple and modern to ornate and traditional. When a person lifts the knocker and lets it fall against the door, it produces a distinctive sound, alerting the occupants inside. Door knockers not only serve a practical purpose but also add character and style to the entrance, making them a popular choice for homeowners looking to enhance the outside appearance of their property.