2012 Yamaha WR450F OEM Balancer Shaft Assy 2S2-11455-00-00. It's a complete unit with the following parts included :
Shaft 1
2S2-11455-00-00
Gear, Balance Weight
2S2-11531-00-00
Weight 1
1DX-11454-00-00
Weight 2
2S2-11464-00-00
Key, Straight
90282-05034-00
Unit look and work like a new one.