Smartwool Classic All-Season Merino Base Layer Crew - Women's Burnt Sienna Small. This base layer features Core Spun technology-which is Merino wrapped around a nylon core for added durability while still keeping the comfort of ultra-soft responsibly sourced Merino next to skin. Our Raglan sleeves eliminate shoulder seams for perfect comfort under a pack and smooth merrow stitching wraps from side to front to keep you looking as good as you feel. Specifications for Smartwool Classic All-Season Merino Base Layer Crew - Women's: Manufacturer: Smartwool Sleeve Length: Long Sleeve Age Group: Adults Apparel Fit: Slim Gender: Female Application: Outdoor Fabric/Material: 88percent Merino Wool/12percent Nylon Features of Smartwool Classic All-Season Merino Base Layer Crew - Women's Our lightweight Merino jersey fabric uses a recycled nylon core while still keeping 100percent Merino wool next to skin Package Contents: Smartwool Classic All-Season Merino Base Layer Crew - Women's Smartwool SW016912Q58100S000: Classic All-Season Merino Base Layer Crew - Women's Burnt Sienna Small