Low oil pressure hose Lifan 140

Hose broadband to lower the pressure in the oil cooler on engine Lifan 140.
It will be installed between the radiator and the engine crankcase (not on the clutch housing). The inner diameter of the fitting has a section of 4mm instead of 2 on the standard fittings.
Hose length 21 cm + 2cm banjo pitch total x2 = 25 cm
To receive a length greater say so in comments.