The file is the third volume of a multi-part compressed archive created with 7-Zip . It is not a standalone file; rather, it contains a specific segment of data from a larger archive that was split into smaller pieces to facilitate easier sharing or storage. Understanding Split 7z Archives
When 7-Zip creates a "split" archive, it divides the total data into sequentially numbered volumes: OK.7z.003
: The first part, typically containing the archive header and index of files. The file is the third volume of a
: The third part, which may contain the end of the compressed data and the final metadata block. How to Open OK.7z.003 : The third part, which may contain the
: The second part, containing the next block of compressed data.
You cannot open the .003 file by itself. To extract the contents, you must have all parts of the set (e.g., .001 , .002 , and .003 ) present. How to recover corrupted 7z archive
It creates 3 parts: * 7z. 001: 32 bytes : Start Header. * 7z. 002: 2968 bytes : start of Compressed Data. * 7z. 003: 81898 bytes : How To Use 7-Zip To Compress & Extract Files - Step By Step