A 2-LAYER CONSTRUCTION WITH FLAT LOCK SEAMS 100 WOOL EXTERIOR AND THE UNIQUE PROPERTIES OF TECHNICAL LIFA REG TECHNOLOGY Helly Hansen Lifa reg Merino Max frac12 zip is our warmest baselayer perfect for any type of activity in cold weather A unique 2-in-1 baselayer with 100 merino wool combined with Lifa reg Stay Warm Technology in a 2 layer construction HH Lifa reg MERINO delivers all the great benefits of merino wool fibres plus the unique properties of technical Lifa reg fibres