ORNOT Merino base layer constructed using Polartec's Power Wool is perfect for cooler days or big temperature swings. This soft fabric places lofted non-itchy merino wool on the inside for tremendous thermal regulation. The synthetic fabric face actively pulls moisture from the merino where it quickly wicks to your outermost layer. This keeps you at just the right temperature whether you're working out, Ornot. Please see size info in photos.