My skates came with washers that were placed on the inside of the wheels that didn't really seem to do much. However, putting these on the inside and the outside of the wheel made a huge difference for me. I'm riding on 57mm hybrid wheels and they just seem to pick up speed with a lot less effort now. Another thing I really like is that now I can tighten my axel nut more and still have the wheels spin freely. Before I was constantly worried I had the axel nuts too loose or too tight.