I got this some years ago and I don't know what I did with out it. It can make those really miserable days out side more comfortable. I have had the inserts last between 2 hours to almost 4 all depending on the weather and my activity level.

Warning never have the inserts in your carry on bag when you fly. After arguing with the TSA for a good long time I got them to not take them away from me. I was not thinking when I was packing when I was going home of what should go in the carry on bag and the checked luggage. I was in to much of a hurry just to catch my flight. Some how I convinced the guy that they where what I said they where after showing him a good number of photos of them on the internet and how I needed them as a mascot performer.