I was told these are the best, so I got them. When they arrived they seemed good quality and the bearing seemed smooth too. I adjusted the “teeth” down as far as I could, as I though they would eat up my shoes, and to my surprise, as well as excellent grip , the “teeth” caused absolutely zero Impact on the soles of my shoes. So good decision. I have been warned they are quite good at scratching your ankles while at rest so do watch this. But enjoy!!😁😁😁👍🏽👍🏽