This genuine Fiat 4591437 ball bearing, often identified by the cross-reference 63204-2RS, is specifically designed for water pump applications in a wide range of Fiat and New Holland agricultural tractors. Measuring 20 mm inner diameter, 52 mm outer diameter, and 15 mm width, this robust and sealed bearing ensures reliable performance and durability. It is a direct replacement for original equipment, guaranteeing proper fit and function across numerous compatible models.