Notes: 123907-22090 PISTON ASSY, 18.5 is original YANMAR product. 123907-22090 PISTON ASSY, 18.52 is commonly used in transmissions/axles/engines 4TNV106-NTB, 4TNV106-NTB, . if you have any questions please do not hesitate to contact us via Whatsapp +17275652849