Helly Hansen Men's HH Dry Base Layer Stripe T-Shirt Lifa Stay Dry Technology Flat lock stitching The fine filament polypropylene yarns used in LIFA are lighter weight and less absorbent that any other natural or synthetic fiber for use in any activity where moisture transfer is necessary to remain comfortable Designed to be worn next to the skin as an active single layer Machine wash low hang dry no bleach do not dry clean or iron