Notes: R208197-P.O.57201487 PLUG TESTA T.D14.6X9.5 is original JOHN-DEERE product. R208197-P.O.57201487 PLUG TESTA T.D14.6X9.51 is commonly used in transmissions/axles/engines . if you have any questions please do not hesitate to contact us via Whatsapp +17275652849