This is a pack of ten 5x10x4mm metal shielded "Speed" 1/8 clutch bearings. ProTek R/C "Speed" bearings are high quality steel/chrome bearings designed for the R/C racing enthusiast.

These 5x10x4mm metal shielded bearings are the standard bearing for the 1/8th scale nitro clutches. Please check the manual that came with your vehicle for the correct size if you are not certain.