Addalock portable door lock
A metal lock that you fit to the door from the inside. The listing says it works on most doors that swing into the room, needs no tools, and fits in a bag.
- Free version:
- The room's deadbolt and swing latch.
- What it adds:
- A second lock that you carry and control.
- Limit:
- It does not fit doors that open outward or slide. Practice taking it off, so that you can leave fast in an emergency.