This system has been a great deal and now I am thankful for it. I've learned my $60 lesson: always verify that the components work well together before the return period expires. I was building a kart from scratch and after putting everything together I found that the caliper didn't close tight enough to actually stop the cart. It was both a disappointment and a relief. It's frustrating that I now have to order and wait for another braking system before I can test drive my newly built kart, but the relief is that I only spent $60 instead of $300 to discover it and be that much money . The first picture shows the pistons fully extended while the second picture shows the gap that still exists. There is a similar gap on the opposite side of the brake disc, but I couldn't get a better picture for this post.