This unit carries a chain around a fixed sprocket wheel mounted on an integrated bearing support, guiding or tensioning the roller chain within the free space defined by its geometry. The sprocket body is made from steel or sintered iron, with a bore diameter of 16.2 mm, an outside diameter of 40.0 mm and a net mass of 0.42 kg. The compact bore-to-outside-diameter ratio keeps the unit suitable for guiding roller chains where limited radial space is available around the shaft. Since the sprocket integrates the bearing function directly in the unit, mounting is simplified to fitting the shaft into the bore, without separate bearing selection or alignment work on site.