Rear Hub Disc Brake Adapter for gas motorized bicycle,OD/ID:2.59mm(2.32in) /37mm(1.45in); Thickness:22mm/0.86in;hole to hole of the distance is 44mm/1.7323inchDisk brake hub adapter is made by cnc machine higher accuratelyWorks with 30t sprocket max unless you are professionalWorks well on rear hub of bicycles with 6 patterns Product descriptionRear Hub Disc Brake Adapter - 48cc/66cc/80cc Gas Motorized Bicycle; This adapter only works for a sprocket 30t maxWorks well on Spoke wheek bikes and Mag wheel bikes Out Diameter: 59mm;Inner Diameter: 37mmThickness: 22mm Rear Hub Disc Brake Adapter for gas motorized bicycleDisk brake hub adapter is made by cnc machine higher accuratelyThis adapter only works for a sprocket 30t maxWorks well on Spoke wheek bikes and Mag wheel bikes ShippingCheck our feedback's to see what our customers say about the FAST shipping we offer Shipping is FREE to all addresses other than Alaska/Hawaii,APO/PO boxes .We ship FAST - We will ship the product on the second business day.We work with all major shipping companies (UPS, USPS, FedEx etc.) and provide TRACKING NUMBER to ALL orders.Please ensure that the address is verified and correct during checkout.We are always working hard to ensure your package arrives as soon as possible. Please understand that some factors like weather, high postal traffic, and the performance of shipping companies are outside of our control. PaymentWe accept payment via PayPal only.We will ship the item as soon as payment is cleared on PayPal. ReturnsWe stand behind our products. We offer a 30 Days Return Policy on items which you are not completely satisfied with.Returns are gladly accepted if it is in the original condition, including all manuals and accessories.You have the option for a full refund or an exchange of the item (subjected to stock availability).When sending in a return, please note that it can take up to 7 business days for the return to be processed. ContactWe take our customer happiness very seriously.We buy and sell online, so we understand the value of trust.If you are unsatisfied with your order, please contact and we will work with you to resolve any issue to your complete satisfaction.We are available 24/7 so you can expect a superior and extremely quick customer servicePlease use the Contact link at the top of the list.Looking forward hearing from you,DONSP1986 Team. Thank you so much for views, We truly care much more your purchasing experience,We are 100% dedicated to your complete satisfaction. if you have any questions,please freely to ask and I will do my best to get back to you promptly!Products usually shipped on the second business day and you will receive message of tracking id.DONSP1986 is registered officially in year 2012 and started business in year 2008, we can provide engine kits, high performance spare parts of engine, motorized bicycle and spare parts of bike. hope you can have a great time when shopping with us.