This is a pack of four 8x14x4mm rubber sealed "Speed" ball bearings. ProTek R/C "Speed" bearings are high quality steel/chrome bearings designed for the R/C racing enthusiast.
These 8x14x4 rubber sealed bearings are the standard outer bearing for the Team Losi 8ight front and rear drive shafts. Please check the manual that came with your vehicle for the correct size if you are not certain.