I really needed these key covers. I’m constantly having to fiddle with different keys to see which works. In the past, I’ve tried marking them with a sharpie, but that does wear off. I’ve tried using tape, that as you can imagine was useless. These key covers are awesome. You just need to remember which color is for which lock. They also help cut down on the noise of the keys clinking together. Since this comes with 30, I’ve shared these with my kids and they are loving them just as much as I do.