The models of stackable insoles are each 1mm high and can be stacked between types A and B as many times as needed, finishing with type C as a cover. The intention is to continue stacking them until the desired height is achieved, placing them underneath the shoe's insole to address minor leg length discrepancies (in my case, my right leg is 7mm smaller than the left one). Their stackable design ensures flexibility, preventing discomfort, and will be a model to your foot after some days of use - as we can see in the image, it was printed flat, but after some use, it deformed to my foot format.