A credit card size device that attaches temporarily to a hinged door in order to prevent the door from opening to ensure privacy in instances where the existing latch may be broken or missing. A front unit and a back unit are connected by an elastic member so that, when in place, tension from the elastic member causes the units to be held against the door to be secured.

A safety bolt device comprising: a drop down bolt, the drop down bolt comprising: a cross-member; a first vertical pin attached to a first end of the cross-member; a second vertical pin attached to a second end of the cross-member; a door receiver configured to receive the first vertical pin, the door receiver comprising: a bolt; a jamb receiver configured to receive the second vertical pin, the jamb receiver comprising: a pin; where the door receiver is configured to attach to a door, and the jamb receiver is configured to attach to the door jamb of the door, and where the safety bolt device is configured to prevent the door from being opened when the drop down bolt has been dropped into the door receiver and the jamb receiver.

A door lock system includes a first component mounted on one side of a door and a second component mounted on the opposite side. The system features a structure that mechanically connects the two components, designed to pass through the gap between the closed door and its frame. Additionally, the system incorporates a communication link between the first and second components.

A door lock system includes a first component mounted on one side of a door and a second component mounted on the opposite side. The system features a structure that mechanically connects the two components, designed to pass through the gap between the closed door and its frame. Additionally, the system incorporates a communication link between the first and second components.