PISTON KIT 04-13 YFZ450 95.00, WISECO 4835M09500 COMP 13:1

Part No. 56-W4835+00A_WI (phoenixmotos.com)
Wiseco 95.00mm piston kit
Yamaha 04-13 YFZ450, 09-13 YFZ450R Dish
(Wiseco part no 4835M09500)