Men's Base Layer TopSlim fit sits close to the body, with room for the garment to move with youHeavyweight 300 Living Lining® provides consistent temperature regulation without adding bulk or weightFour-way stretch fabrication for enhanced mobilityQuick drying and highly breathableChafe-free chin guard and softlock seams for added comfortbluesign® approved materials use only safe chemicals and reduce impact on both humans and the planet during manufacturingLIVING LINING HEAVYWEIGHT 300: 92% POLYESTER, 8% SPANDEX Did someone call for climate control? This men's Burton Heavyweight X Base Layer Quarter-Zip will do the work. Highly breathable, heavyweight fleece keeps you cozy even on the coldest of mountain days, and four-way stretch works to give you all the flexibility you need for a solid day of riding. Bonus: you can still keep your friends close, thanks to the stink-resistant finish. (You're welcome for that one.) Burton Men's Heavyweight X Base Layer Quarter-Zip