This Caterpillar 131-6645 Radiator Hose is a genuine OEM part with an inner diameter of 57.2mm. Designed for use with Caterpillar equipment, this hose is made in the United Kingdom and is compatible with various heavy equipment models. Constructed with high-quality materials, this radiator hose ensures reliable and efficient engine cooling. However, it is important to note that this product comes with a California Prop 65 Warning for potential cancer and reproductive harm. Overall, this Caterpillar Radiator Hose is a must-have replacement part for your heavy equipment needs.