Features: *Bicycle Front Derailleur Clamp Band Adapter 34.9 to 31.8 Washer Backing Ring * brand new and high quality *Made of high quality materials, durable and practical *Applicable to most 34.9 hole diameter front derailleurs on the market *Can be used for conversion of from derailleur hole diameter *The use of this plastic backing ring requires that the installation location of the front derailleur should have a inner grooove *Mounted at the position where the front derailleur contacts with the middle tube for realization of the conversion of hole diameter from 34.9 to 31.8 Specifications: *Material: Plastic *Color: Black (As Pictures Show) Package Contents: 1*Front Derailleur Backing Ring Note: 1. The real color of the item may be slightly different from the pictures shown on website caused by many factors such as brightness of your monitor and light brightness. 2. Please allow slight manual measurement deviation for the data. 【High Quality Materials】We use high quality materials to manufacture our products to ensure their quality and durability, and we are committed to providing excellent product quality. 【Sturdy and Practical】Our products have been rigorously tested and verified and have excellent durability and practical functions. No matter when and where you are, our products will consistently provide you with reliable performance and service. 【Easy to Use】Our products are simple in design and intuitive to operate, making them easy to use even for novices. We focus on user experience and hope you can enjoy the use process easily. 【Provide you with help and fun】Our products are designed to provide you with help and fun in your projects, our products will be your right-hand assistant, bringing you a pleasant and satisfying experience. We look forward to your choice and are willing to share this fun with you. 【Excellent After-Sales Service】No matter what problems you encounter, we will solve them for you in time to ensure your satisfaction and shopping experience. If you have any questions about the product, please contact us and we will respond to you within 1491 hours.