The ALPS AK liner is engineered with the same gel properties as our Easygel. Specifically designed for transfemoral and active Below Knee amputees, ALPS AK liner has 80% less vertical stretch than ALPS other gel liners. This provides more control and stability. Here are a few of the built-in features that you will find in the AK Gel Liner from ALPS: Limited vertical stretch reduces movement of redundant tissue. High circumferential stretch to assist with form fitting. Wider distal end for ease of donning. Distal ends are proportionate to the size of the liner.