INA Aux Belt Tensioner 534011020. This belt tensioner is a high-quality component designed for v-ribbed belt systems. It has a width of 24.8 mm and an outer diameter of 70 mm. Please ensure compatibility with your vehicle before purchasing. We cannot guarantee fitment in all situations, so it is important to check all relevant specifications such as dimensions and type. Next day dispatch available for orders placed before 3:00 PM Monday to Friday.