The .7z format is used to reduce the file size of the video for easier sharing or storage, or to bundle multiple files together.
Always ensure the source of compressed files is trusted, as archives can be used to hide malicious software. 335.mp4.7z
The extension indicates a 7-Zip ( .7z ) compressed file containing a MP4 video file ( 335.mp4 ). The Unarchiver (macOS)
You will need archive software such as 7-Zip (Windows), The Unarchiver (macOS), or similar apps on mobile to "extract" or "unzip" the .mp4 file before it can be played in a media player. 335.mp4.7z