This is a pack of ten ProTek R/C 5x10x4mm Rubber Sealed Flanged "Speed" Bearings. ProTek R/C "Speed" bearings are high quality steel/chrome bearings designed for the R/C racing enthusiast. These bearings can be used in any application that requires a 5x10x4mm flanged bearing. Please check the manual that came with your vehicle to determine if these are the correct bearings for your application.