A delivery door extension that attaches to an existing door jamb and engages with an existing door is provided. The delivery door extension includes a panel having a planar body with opposing front and rear surfaces extending between first and second side surfaces, a top surface, and a bottom surface, wherein the panel body includes an opening. The delivery door extension also includes a delivery window body configured to move between an open position and a closed position, a hinge mechanism attached to the first side surface of the panel, a blocking mechanism on the second side surface that restricts movement of the existing door, and a frame that includes first and second portions.

Receptacle locking devices are disclosed. A receptacle locking device having a contact arm and a pivoting feature can be pivoted from a first, unlocked position to a second, locked position, wherein the contact arm prevents opening of the receptacle door when the locking device is in the second, locked position.

Receptacle locking devices are disclosed. A receptacle locking device having a contact arm and a pivoting feature can be pivoted from a first, unlocked position to a second, locked position, wherein the contact arm prevents opening of the receptacle door when the locking device is in the second, locked position.

Receptacle locking devices are disclosed. A receptacle locking device having a contact arm and a pivoting feature can be pivoted from a first, unlocked position to a second, locked position, wherein the contact arm prevents opening of the receptacle door when the locking device is in the second, locked position.

A delivery door extension that attaches to an existing door jamb and engages with an existing door is provided. The delivery door extension includes a panel having a planar body with opposing front and rear surfaces extending between first and second side surfaces, a top surface, and a bottom surface, wherein the panel body includes an opening. The delivery door extension also includes a delivery window body configured to move between an open position and a closed position, a hinge mechanism attached to the first side surface of the panel, a blocking mechanism on the second side surface that restricts movement of the existing door, and a frame that includes first and second portions.

A delivery door extension that attaches to an existing door jamb and engages with an existing door is provided. The delivery door extension includes a panel having a planar body with opposing front and rear surfaces extending between first and second side surfaces, a top surface, and a bottom surface, wherein the panel body includes an opening. The delivery door extension also includes a delivery window body configured to move between an open position and a closed position, a hinge mechanism attached to the first side surface of the panel, a blocking mechanism on the second side surface that restricts movement of the existing door, and a frame that includes first and second portions.