Excellent bearings, in my opinion these are the best V-groove bearings you can find at a reasonable price. The only downside is finding a track that suits them. I used a steel angle but a V-groove rail works best. This gives you the option to use it on either the AV Groove Track or the AV Groove Channel, basically in the corner. This gives you tremendous flexibility in terms of price. Definitely will buy again. The seller also shipped as soon as possible!