What exactly are those small metal square attached to the inner side of a wheel for? Im thinking to balance out a wheel, I think. I just did a search and had no luck. The reason Im asking is because I noticed a few are coming loose, almost ready to fall off and I think some are missing because when I got my wheels they had maybe 4-5 of those things. Now my left rear wheel only has two left and those two are really loose. I am wondering what will happen when they all do fall off. Im noticing Im getting a lot more tire noise from my tires latetly, many this be a cause (out of balanced wheels). And no its not bad wheel bearings, thats been checked on all fours. Also, had an alignment done not to long ago. Thanks.