7-Zip will automatically read the subsequent files and combine them back into the original file. To help you further, could you please clarify:

Like standard .7z files, split files use LZMA and LZMA2 compression, allowing for significantly smaller file sizes compared to traditional ZIP formats.

Here is a detailed breakdown of the features and how to handle this type of file. Key Features of 7z Split Archives

Ensure you have the latest version of 7-Zip installed, as it is the native tool for this format.

Despite being split, 7-Zip recognizes the set as one entity. You only need to interact with the first file ( .001 ) to extract everything. How to Extract .7z.021 Files

Supports AES-256 encryption to secure sensitive data, even when split across multiple files.

(If parts are missing, you won't be able to extract).

while trying to extract it? Which operating system are you using (Windows 10/11)?