Replacement for the stuff that came on my 2012 Highlander. They appear to be one piece rather than the chrome nut covers that are standard on many cars today. The original nuts can fail in two ways: they can rust internally and they can swell in the housing, making a standard 19mm wrench unfit. In my case it was the use of impact wrenches, either from the dealer or a tire shop I used to change my winter tires. Shells can deform on impact and the result is the same. The standard key no longer fits. I will update this review when they move out.