Notes: 129F01-22900 PISTON ASSY, 0.25 OS is original YANMAR product. 129F01-22900 PISTON ASSY, 0.25 OS4 is commonly used in transmissions/axles/engines 4TNV94FHT-NKK, 4TNV94FHT-NYEM2, 4TNV94FHT-NYEM2, 4TNV94FHT-NKK, . if you have any questions please do not hesitate to contact us via Whatsapp +17275652849