Advise a way of synchronization of files

There are two windows computers. I would like to synchronize certain directories between them in both directions. Requirements:
- a minimum of explicit synchronization actions (for example, you do not need to run a special command to delete a file, just delete it using the OS tools)
- accessibility of folders in the absence of the Internet (a disk connected remotely or a samba server seems to drop out here)
- preferably with a minimum set to an outside company.

Files are mostly large and binary, so svn is not very convenient.

What do you advise? And I’m already tired of carrying a flash drive with me.