The versatile Women’s MERINO 150 Base Layer Micro Stripe Short Sleeve from SMARTWOOL can be worn on its own, or as a base layer. Core spun technology combines merino wool with nylon, so it maintains all its breathability and moisture-wicking qualities of merino with the durability of nylon. The raglan sleeve design and stretch merrow stitching provide a comfortable fit with a full range of motion. The Ultraviolet protection factor of 20 means you’re protected against the sun on hot days.