Got as a gift at the wrong time of year and it didn't fit my son by the time the weather got cold! From website: "Top-to-bottom quick-drying warmth and versatile lightweight comfort in one convenient package. Matching top and bottom base layers are paired up in a convenient, all-in-one package with the kids' Burton Lightweight Base Layer Set. Stretch, breathable, and quick-drying, this technical head-to-toe combo keeps boys and girls warm and dry whether they're on the mountain or just on the couch. Softlock seams and anti-pilling properties mean long-lasting chafe-free comfort, and stretch performance gives junior double-jointed dexterity without bunching or un-tucking. Features: Regular fit is just right: Not too tight or too baggy DRYRIDE Ultrawick is highly breathable and ultra fast wicking Bird's eye mesh fabrication Two-way stretch fabrication for enhanced mobility Set includes a top and bottom Chafe-free softlock seams for added comfort"