H8027.7z.004

This indicates it is the 4th volume in a sequence. You cannot open this file independently; it is a "chunk" of data rather than a complete standalone file.

To extract the contents, you must have of the archive (h8027.7z.001, .002, .003, and .004) in the same folder: h8027.7z.004

The file is the fourth part of a split compressed archive created with the 7-Zip utility . This indicates it is the 4th volume in a sequence