I was an owner and user years ago of those €20 splints with an air pump that you inflated yourself as it suited you... I had to buy this one because of an emergency! The green gel is just like a "touch" or a sample at the bottom of the case, and the rest is empty plastic. For a product that costs €40 at the pharmacy, this looks like a joke. Nonexistent cryotherapy: For cryotherapy to work properly, the gel must evenly cover the entire ankle area and have enough volume to keep the cold. With this tiny amount, the gel freezes for only a few minutes and then immediately warms up from body temperature. To my shock, I found that the air inside is factory pre-installed and minimal! Also, one of the two plastic parts has no air at all, as you will see in the photos too. In closing, I find that for these reasons its fit is not the best compared to those with an air pump, and in practice your socks save you. What a pity! In the end, sometimes the expensive is just expensive and nothing else.