Notes: 129636-22900 PISTON ASSY, 0.25 OS is original YANMAR product. 129636-22900 PISTON ASSY, 0.25 OS2 is commonly used in transmissions/axles/engines 4TNV88-SND, 4TNV88-SND, . if you have any questions please do not hesitate to contact us via Whatsapp +17275652849