The top rack of our dishwasher has two rubber stops on the backs of the arms. They fold and clip on to the arms. Over time, the clip let go, the stop falls off, and pulling the rack out causes the arm to fall free from its retaining wheels, sending dishes crashing if you don't catch it. We put them back time and time again, but eventually one broke in half. Given the brand and model of our dishwasher, I was able to locate the part on AppliancePartsPro.com quickly, and ordered it with regular shipping - and was pleasantly surprised to get it the next day! It's a simple fix, no tools necessary, just long arms. Thank you.