TNU Extension

I don’t know what codecs I need, or anything for this file extension, I am sure it is for movies. Can anyone help?

I changed .tnu to .rar and was able to extract the movie which had an .mkv extension which windows media player 10 aws able to play.I hope this helps.

How do you play .tnu files? And how do you convert it to .rar? Isn’t there a codec or player to play .tnu files?