Helly Hansen | Women’s HH LIFA Long-Sleeve Crew Base Layer Size Medium No matter the season or activity, HH LIFA® base layers ensure warmth, dryness, and comfort. With our revolutionary hydrophobic LIFA® technology, you'll experience lightweight insulation and efficient moisture management. Whether it's for daily wear or high-performance pursuits, our base layers have excelled in LIFA® technology for four decades. Lightweight insulation 100% LIFA® Flatlock seams for max comfort Natural stretch fabric