The Merge Hose Re-Routing Kit Changes the coolant flow from Series to Parallel, the OEM routing sends the coolant flow to one radiator and then from there over the other side. This original routing allows the coolant to partially short circuit to the first radiator, coolant (water) will always flow in the easiest direction. This MRT kit forces the water to split and utilize both radiators more effectively which helps keeps the temperature down.
This Product will fit these modelsHonda CRF250R 2018-2021
Honda CRF450R 2018-2021