I bought a set of chain eye nuts and installed them in the middle of summer with the included 7 point spline tool. When I went to swap tires yesterday, two wheels came off and the spline tool broke. It broke along the entire length of the outlet. I used the hand tool that came with my Nissan Altima to loosen the lug nuts, I didn't use any electric or pneumatic tools. The nuts aren't too tight either. I think the walls of the star spline tool are so thin that they don't have much power. The only other review of this tool had the exact same issue. Hopefully a redesign is in the works. Circuit Performance nuts are great, you just need a reliable way to tighten and loosen them.