Secondary marketplaces like Judecca Comic Collectors use "2bks" to denote a lot of two physical books (e.g., "Lot of 2bks").

You will find this shorthand on various platforms and marketplaces to describe bundled items:

When downloading .rar files from unofficial sources, always ensure you have active antivirus software, as these archives can sometimes contain malicious executables disguised as documents or media. Flash 275 | Judecca Comic Collectors