INA KBO2558-PP-AS Linear Guide Ball Bearing
You will find that the standard bearing steel gives this component a familiar, no-nonsense strength that works well in everyday setups.
FAG Spherical Roller Bearings 22218E / Unused in Original Packaging
I like that the 6303-2RS is easy to find and fits common hobby motors without fuss.
FAG Spherical Roller Bearings 22215 Esk.tvpb/Unused in Packaging
With the 6004-ZZ shown, I feel like I know exactly what I’m getting before it arrives.