Notes: 1990752 - p/o 20231 BRAKE PISTON (012076 ) PISTONE FRENO - B is original CATERPILLAR product. 1990752 - p/o 20231 BRAKE PISTON (012076 ) PISTONE FRENO - B1 is commonly used in transmissions/axles/engines . if you have any questions please do not hesitate to contact us via Whatsapp +17275652849