Right-click the .001 file and select "Extract" using 7-Zip. The software will automatically bridge the segments to recreate the original .mp4 file.
Confirms this is the second segment of the larger video file. Usage Instructions Mia-FD-Mia-046b-Part2.mp4.7z.002
Likely a sequence or version number within a larger collection. Right-click the
Ensure you have Mia-FD-Mia-046b-Part2.mp4.7z.001 and any subsequent numbered parts. Mia-FD-Mia-046b-Part2.mp4.7z.002