O.E. style replacement 16T front sprocket for 81-83 Yamaha XJ550 H/J/K Maxim, 81 Yamaha XJ550 R H Seca, 82-83 Yamaha XJ550 R J/K Seca & 84-85 Yamaha FJ600 L/LC/N/NC. If you wish to order a different size sprocket to change your gearing, feel free to give us a call to order the size you desire.