Description of Sierra Designs Drizone Packable Bootie Slipper - Women's:
The Sierra Designs Women’s Drizone Packable Bootie Slipper gives you waterproof warmth for everything from tent-bound card games to blizzard days spent curled up on the couch. A waterproof breathable Drizone shell seals out snow and moisture, while the PrimaLoft synthetic insulation provides big warmth that insulates even when wet. A nylon, non-slip sole adds grip on slick floors or outhouse trails, and an elastic cuff keeps the slipper on your foot. Sierra Designs even added a stuff sack for easy packing.
Bottom Line: When you’re not wearing your boots, you should be wearing these toasty booties.
I bought these to sleep in since I get very cold feet in my sleeping bag. They were not as thick as I had expected, but they were comfortable. I wore them over a thick pair of wool socks and my feet stayed warm. Without them, I would wake up with feet of ice, so they obviously did the trick. However, if the temps were much below 25F, I would upgrade to some down booties.
I wore them around camp while making dinner, etc. and they held up well.