Product name : chain roller Color : As Picture Show Inner diameter: 10mm Item variety : power belts Note : 1.We provide clear images ,measurement where possible.Please examine as a lot as possible to ensure the item the one that you need. 2.The actual merchandise perchance has slight colour distinct with directory image because of diverse laptop displays ,thanks for your understanding. 3.The size of item is guide measurement,please allow 0.5-1inch difference.(1inch=2.54cm) 4.No instruction .Professional installation is Highly Recommended! Package integrated :1 x chain roller