A file with the extension .F4V is an 'MP4' video file utilised by 'Adobe Flash Player Version 9' and later versions.

The file name .F4V was designed to eliminate compatabilty problems between the Adobe Flash Player / Quicktime / iPod's / etc. whilst using certain .MP4 video files.

Flash Player 9 allows you to enjoy the most expressive, engaging experiences on the Web that combine interactive, rich content with video, graphics and animation.