Premium Sprocket 5-hole 55 teeth. 101 Octane Premium sprockets are laser cut in Europe using thermo-mechanically rolled fine-grain steel ALFORM 460 EN 10149 and therefore have a better, wear-reducing tooth geometry with optimum strength. Laser cutting ensures a significant weight reduction and a unique design. An impact-resistant KTL coating also protects against unwanted scratches. The durability of these sprockets is 2-3 times higher than conventional sprockets. Fits Aprilia RX, Explorer, Generic, KSR motor Keeway and ride mopeds. Mounting hole: 8.5 mm Inside diameter: 105mm Number of Holes: 5 PCD: 120mm standard: 420 offset: no / Teeth: 55