When they first arrived I was disappointed because they seemed thin, but looks are deceiving. With both layers these are quite warm and I even found myself pairing back a layer a few miles into a run when it was about 30 degrees F.
Absolute best mittens ever. I have several pairs - been using them for years. Only thing that keeps my hands warm on long, cold trail runs in the winter.
The most versatile pair of mittens you'll find. Covers an incredible amount of temperate range and even helps block most precipitation, esp snow. Love em!