JR LIFA MERINO MIDWEIGHT SET. JUNIOR. Shell: 57% Merino Wool, 43% Polypropylene. Our warmest juniors' base layer set, combining unique Lifa® wicking technology with merino's natural breathable warmth. The best kids' base layer on the market uses a clever 2-layer construction to keep active youth dry and warm. Our Lifa® technology wicks away moisture while soft merino wool creates breathable warmth. LIFA® MERINO|LIFA® STRIPE|Elastic waist|Flatlock seams for extra comfort|Non-itch fabric|Solution Dyed|ZQ wool