We just returned from 10 nights at various resorts at the parks. Our kids like to trade pins, and several years ago a CM recommended we get the locking backs for the pins so they didn't fall off of the lanyards. The locking backs are gold and look a bit like a bullet casing, and they require a special tool to get them off and on. Well, we've never had a lot of luck finding the backs, usually the stores are out of them. At the beginning of this trip we couldn't find them anywhere, which meant that the kids didn't want to wear their lanyards because the small rubber Mickey backs just don't hold well enough to be trusted. By the middle of the trip all the stores had them in stock again, but after buying a few bags (to keep on hand), we realized that they were defective. The little black tightening mechanism didn't tighten completely. A CM at the Pin Trader store at DTD sat with my husband and went through bag after bag of these things and couldn't find an entire package that worked. Occasionally they would find one or two in a bag that tightened enough, but none that fully tightened. That store pulled every bag they had off the "shelves." When we went to other stores and found the locking backs, we'd ask to try a few and see if they worked. The CMs looked at us like we were crazy, but they'd let us try. We never did find any that worked, but no other stores took them off the sales floor. Apparently, it is quite common for them to be defective. One CM told us that the last batch they got in had a different problem, I think the little tool didn't fit in the hole or something. Just a warning for those of you looking for these. It is heartbreaking to buy or trade for a cool pin and then find out the back failed and the pin is gone.