These little gel cushions really are feet savers!
I have a really cute pair of stiletto suede ankle boots but the very high heel means that the balls of my feet start to burn after half an hour!
I bought a pair of these, popped them in, repositioned them once or twice to get them in the right place and what a difference!
My feet still feel tired and achy at the end of the day (because I don't wear heels all that often) but the balls of my feet no longer burn in pain.
The gel cushions stay put and don't move, although the package does say that they're reusable and washable. I haven't washed mine, but I have wiped them with a damp cloth and will be leaving these in this pair of shoes until they need to be replaced.
I'd rather buy another pair if I ever need to put any in a different pair of shoes.