Review on High-Quality Miniature Skateboard Bearings - 8X22X7mm Bearings for Smooth and Effortless Skating by John Floyd

These bearings are suitable for most low load, low speed applications. I use them in several of my 3D printed projects. The bearings are pretty greasy and one of my kits was missing a seal. I would still buy them again as they are quite cheap and fit my small projects. If you are looking for a high speed or high load bearing I would look elsewhere and buy something better.