One of my legs is about a quarter inch longer than the other and these little heel lifts work wonderfully for me. I like that you can vary the height and that there's sticky backs to stick the lifts together - though you can still peel them apart even if I've never had them come apart on their own. They do not stick quite as well to the insole of my shoes, but I've only had to reposition one once - which is so much better than the rubber 'non-slip' ones that I had been using. These are also somewhat gel-like, which means that I can be on my feet at work all day and I don't get added pain. The only thing that could be improved is that all the layers are the same length and if you're like me and need all three layers, at the edge they feel like a big lump in the shoe. I remedy that by cutting the lifts back a little in steps, which works well. (Just make sure you have a good pair of scissors.)