Notes: 129001-22901 PISTON ASSY, 0.25 OS is original YANMAR product. 129001-22901 PISTON ASSY, 0.25 OS5 is commonly used in transmissions/axles/engines 4TNE88-NSW, 4TNE88-NSR, 4TNE88-TB1, 4TNE88-ETBZ, 4TNE88-TB, . if you have any questions please do not hesitate to contact us via Whatsapp +17275652849