Spacers look nice in terms of fit and finish. The price is less than half of what some others charge for similar products. More expensive spacers come with 12.9 lugs, which I don't see as an upgrade as they require more torque and are more brittle. They come with unmarked red liquid with no instructions. I'm a bit concerned about Eccpp's answer that it's "thread glue" and they can't explain why it's needed. If you change wheels frequently, this is a problem. Threadlocker also prevents the wheels from being ridden after a few miles, which is recommended. It's almost certain that Eccpp isn't developing this product, but since they probably copied an existing product, they should work just fine.