TARIC 8483.50.80.30 — Mechanical tensioner for maintaining the tension of the drive belts of a passenger car engine: -with two pulleys made of polyamide, each of them with a diameter of 50 mm or more but not more than 70 mm, -with a spring made of a steel alloy containing chromium and silicon, -with two arms made of aluminum, -with a holder made of aluminum, for use in the manufacture of motor vehicle engines