Push-on hose with a 1 1/2 inch, 38.1mm internal bore. At this size it is well beyond typical fuel plumbing and belongs to bulk transfer work: coolant and radiator plumbing, header tank and swirl pot connections, large breather runs and similar high-volume, low-pressure duties. It is used with correspondingly large push-on barbed fittings, where the barb grips inside the bore. Realistically a hose this size needs a clamp regardless of pressure, simply because of the surface area involved and the effort required to seat it fully. Use assembly lube liberally. It is not compatible with PTFE, nylon braided or stainless braided hose ends.