This is a pack of four 8x14x4mm rubber sealed flanged "Speed" ball bearings. ProTek R/C "Speed" bearings are high quality steel/chrome bearings designed for the R/C racing enthusiast.
These 8x14x4 metal shielded bearings are the standard bearing for the Team Losi 8ight differential outdrives. Please check the manual that came with your vehicle for the correct size if you are not certain.
I personally never have had a problem with the ProTek bearings. I have been using them for a few years now in my 1/8 scale Losi buggy and truggy. I would recommend them to all.
Horrible, they didn't last a race weekend, one came totally apart and I couldn't finish my main. I don't have this problem with the stock Losi bearings. The real bargain is spending the money on good bearings!