There is no question that these were Thule locks, but maybe they were just too old for this person to be familiar with. I found the sound to be too tinny and harsh and wanted to adjust it. They barely fit, though. These are now officially the best slippers I have ever had! Just house slippers. I am on my feet the whole time. So without that in mind it?s a okay piece of equipment. I live in South Florida and these are my first wool slippers. Sizing all wrong! So I wear a size 8.