COLD WEATHER BASE LAYER. Our Kids' Base Layer Bottom uses super-soft interlocking knit—perfect for layering in cool conditions or for wearing alone on a mild day. Now your kids can be as warm, dry, and comfortable as you are in your Smartwool base layers. SLIM FIT. Designed to meet the demands of outdoor adventuring, these slim fit bottoms rest easily under layers while offering unrestricted movement through the legs. Inseam: 20" CLASSIC THERMAL MERINO. Ideal for cold-weather activities where warmth and breathability are crucial, this midweight fabric used a 100% Merino wool construction that helps move moisture away from skin to keep them warm and dry. FUNCTIONAL FEATURES. They'll Go far, feel good with thoughtful tech to keep them trekking comfortably — interlock knitting enhances breathability, thermoregulation and moisture-wicking while flatlock seams minimize chafing for their greater comfort. GO FAR. FEEL GOOD. From wool socks to base layers for men, women and kids, we aim to provide the highest quality apparel for your outdoor adventures with a commitment to environmental sustainability, racial equity and inclusivity. It's the little things that make up the big ones. And we really need to sweat the details to make sure that we're taking care of the big picture. To us at Smartwool, the big picture is simple to identify — defeat climate change and make sure everyone has access to the outdoors. But it's the small choices we make every day that will make sure we get there. For us, it doesn't just start with our product, but with our community and our planet. That's why all of our Merino wool products — from hiking, running, and ski / snowboard socks to base layers, mid layers, outdoor apparel and more — come with our guarantee to remain commited to enviromental sustainability, racial equity and inclusivity, plus frequent artist collabs to stay on the forefront of high quality, sustainable fashion. Once you experience our Merino wool, you'll realize that a better future is possible. Go far. Feel good.