05 Honda Rubicon, Can't find/identify this gear.....

I am currently building an 05 Honda trx500 FGA '05 - Its my biggest project yet as i am not the one who took it apart... My problem is as I am rebuilding the engine I have a gear I need but i'm not sure what it is called, I've looked on babbits, partzilla, and my manual, all with no luck!:|:| If anyone could point me in the right direction, it would be greatly appreciated!!