Well, I have to say that the inserts that come with these mittens are rather wimpy as in durability. They actually sent me a large and a medium, but they still work fine so no worries. The mittens have kept my hands warm on my trekking pulls for a couple of cold days. It really hasnt been cold enough yet on the AT to warrant everyday use. I notice the linings in the mittens are just ok. The thumbs tend to bunch up as you put them on and take them off, so you need to take the extra time to take them off carefully. All in all these mittens are worth the money :-)