Package Include: 1pc Bike PulleyBrand new with high qualityName: Rear guide wheelMaterial: 7075 high-strength aluminum alloy + metal PalinSize: 11T diameter of about 41mm, 13T diameter of about 49mmColor:Black/Red/Blue/Green/Purple/Gold/Silver/PinkSpecification: Guide wheel with 4/5/6mm shaftWeight: 11T 6.9g 13T 8.8gFor the purchase of 11T and 13T, 13T is usually considered for long-tail rear dialing, otherwise 11T guide wheels are used.7075 aluminum alloy material. Support most dialing on the market, support 7/8/9/10 speed!Quantity:1pcGuide wheel selection rules: Please try to use the same size as the original guide wheel. There is no difference, you can choose smaller than the original guide wheel, but you can not choose a large.Selection principles: 1: Use the same size as the original guide wheel as far as possible, and there is no difference. You can choose smaller than the original guide wheel, and you can not use large ones. 2: The guide wheel and the tension wheel are not distinguished. Some original rear guide wheels and the tension pulley are not the same in size and can be replaced. It is necessary to re-adjust the length of the chain.Notice:1.1cm=10mm=0.39inch.2.Please allow 1-2mm error due to manual measurement and make sure you do not mind before ordering.3.Please understand that colors may exist chromatic aberration as the different placement of pictures.