For Nissan 240SX S13 3-Ply Silicone Radiator Coolant Hose (Blue) - 1st Gen KA24 Silvia 3-Ply (4mm) Nylon for Strong Reinforcement Increases Engine Performance and Efficiency and Helps to Keep Engine Bay Temperatures Cooler Withstands Operating Temperatures up to 330F Degrees Fahrenheit Main Hose Inlet/Outlet Inner Diameter: 1.25"/1.25" / Size (Diameter) Tolerance: +/- 0.225" Work With Factory or Aftermarket Radiators