Gates HK4RB Blue Racing Hose Kit Durable nylon fiber provides extra wear resistance, doubling tooth strength Kit contains 1-Upper radiator hose (22919 - 13.9 inch centerline length, 1.2 inch inner diameter) and 1-Lower radiator hose (21871 - 27.6 inch centerline length, 1.19 inch inner diameter). Protects against the high temperatures of full throttle driving Combats the leading cause of premature hose failure - electrochemical degradation (ECD) High saturation HNBR elastomeric composites contribute to the exceptional durability and heat resistance with aramid reinforcement