Can you help ID this rotor?

[Jimmah]

I bought this rotor being told it was for a 03 Z400 rear but it does not. Any Ideas to what it may fit? It has R-ROT4 etched on it. Thanks.

http://i141.photobucket.com/albums/r55/juniorbacon/ebay/IMG_1474.jpg

[Colby@C&DRacing]

it fits a rear trx450r