Resin twin hose (triplet) is extensively used in the fields of forklifts, farm machinery, auto brake control, hydraulic machine tools, lubrication equipment, mining machinery, ships, aerospace, etc., with high loading capacity, excellent impulse performance, small fluid resistance, high toughness, good fatigue resistance, small bending radius (excellent bending property, difficult to break), excellent abrasion resistance, high cleanliness, low expansion rate, low temperature resistance, hydraulic grease resistance, and anticorrosion of chemicals such as alkali, aging resistance, use stability, long life, etc.