I bought these because I knew the bearings were going to be crap. Surprise surprise, crappy bearings. That being said, I bought these because I needed pillow blocks for the other bearings I bought Pros: The bearing blocks are well made, it was cheaper to buy these bearing blocks than to buy a pillow only blocks Cons: Crap bearings Be sure to buy the LM8UU package with them as you will get most of them , if not all, need to be replaced with new bearings.