brand new and high quality brand new! Material: Metal Tooth Number: 11 tooth / 14 tooth / 17 tooth /20 tooth (Please let us know the tooth number you'd like.) 11 tooth size: 30mm(Diameter) x 12mm(Thickness) 14 tooth size: 40mm(Diameter) x 12mm(Thickness) 17 tooth size: 47mm(Diameter) x 12mm(Thickness) 20 tooth size: 55mm(Diameter) x 12mm(Thickness) Placement: Front Fits 47cc & 49cc Dirt Bike engines. For use with 8mm T8F chain. Note: 1. (IMPORTANT) No Instructions Included.Professional Installation Is Highly Recommended 2. Please check the size measurement chart carefully before making payment. 3. Please allow 0.5-1 inch difference due to manual measurement.(1 inch=2.54cm) 4. The color of the actual items may slightly different from the listing images due to different computer screen, thanks for your understanding. Package included: 1x Chain Cog