Determing size:  What the Heck is "Mondo"? 
Mondo is a European sizing system that is determined by Centimeters, and not random sizes like “8” or”10”.

How to Measure: 

To find your Mondo size, place your foot on a piece of paper and mark your longest toe and heel of your longest foot, or stand against a wall and mark the longest part of your foot on a paper. Measure this distance in Centimeters (inches X 2.54). This is your Mondo size.

Do not convert your Mondo size to your US size or vice versa: it won't work, and you will end up with the wrong boot size. Use the steps we have listed above, then downsize to the nearest whole size.

The sizes are from *.0 - *.9. If you measure a 26.7, let’s say, then you would downsize to a size 26 because the shell/liner will fit a size 26.0 – 26.9. If you go to a size 27, now you are in a boot/liner that fits 27.0 – 27.9. Downsizing is recommended, but if you have questions regarding sizing/foot issues, call or email us and let us help.

What to expect:

When you first get your Thermo Flex liners and put them on your feet, THEY WILL BE UNCOMFORTABLE. This is because they are not molded to your foot, they are designed to some generic form. Also, they will be hard and will probably poke and prod your feet in places that feel strange to you. You must heat the liner to mold it to your foot - we suggest that you take this to a professional.

You may think they don’t fit. But before you call us to return, please do this simple Shell Test:

  • 1. Take the liners out of your boots.
  • 2. Put your foot back inside the shell (not the liner), stand up, and push your toes to the front of the boot (not squished).
  • 3. See how many fingers you can get between your heel and the back of the shell. Fingers on top of each other NOT side by side.
  • 4. If you can get 1-2 fingers back there, from our experience we have found the boots will fit once the liner is molded. If you get more (say three+ fingers), the boot will be too big. If you cannot get even one finger back there the shell is too small.
  • 5. If your boot shell and liners are the same size, the liners will fit after you mold them.
  • This is purely a guideline and what has worked for us; ultimately it is your decision whether or not you want to keep the size or return the boot/liner. Remember, once you mold the liners or wear them anywhere but on the carpet, the boots/liners are yours.

    If you still want to return the liners, you must call or e-mail us for an RA number. Without this RA number on the outside of the box we will refuse the package, and you will get the boots back again.

    Molding the Liners:

    Once you have decided to keep them and now want to mold the liners, we recommend taking them to a professional boot fitter.

    Reason: this is what they do for a living, and their experience is vast.

    Additional reasons: There are certain techniques and tools that the professional will employ to make sure your boots fit perfectly. The oven they use is specially designed to mold ski/snowboard boots and only heat the liners to a certain degree. Usually, a ski/snowboard shop will charge a very nominal fee (relative to the cost of your feet throbbing in pain) to mold your liners for you.

    We do not endorse the "do-it-yourself" school of thought. Your feet/boots are your main and only connection with your board. Could you do this at home? Maybe. But is the chance to screw up your 1st day in your boots worth the few bucks it would cost to have a professional mold your boots? We don't think so.