Specifications:Material wheel: TPU filamentColor:blackMaterial : 29.2mm stainless steel A4Flanged ball bearing 4x10x4mmCompatibility For Ro. borockmodels: S7, S7 Pro, S7 MaxV, S8, S7+, S6 MaxV, S6 Pure, S6, S5, S4Q RevoS8 seriesS7 seriesQ7 seriesS6 seriesS5 seriesS4 seriesS7 seriesPackage Contents:1*Rubberized front wheel, including axle and ball bearingNote: 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.————————————————Sincerely welcome you to purchase! We pursue excellent quality. If you have any questions after placing an order or purchasing a product, please feel free to contact us at any time. We will provide you with thoughtful service!