A portable door lock that can be installed in seconds without the need for tools. Use it at home, take it with you when you travel, for living situations, apartments, apartment living, hotel students, and school lockdowns. This is a portable door lock that can be easily attached to and detached from an open door. The portable lock can be used when staying in hotels, private lodging, or other short-term rentals on business trips or domestic and international travel. It is also possible to lock a room without its own key. You can easily ensure security and privacy, and spend time in your room with peace of mind. It is very suitable for students to use as an economical security lock-in option. Especially overseas, it is often difficult to use hotel and private lodging keys, and it is often difficult to feel safe, but by adding it to an existing door lock, you can enhance security, and it is reassuring to have one.