The Warm Flow takes the best of natural and synthetic by combining merino wool and Helly Hansen's famous Life fabric in a two-layer construction which creates a great base layer for cold conditions.
The Lifa Flow fabric apparently moves moisture away from the skin faster than any other baselayer technologies on the market, whilst the merino adds a great feel to the garment. Add to that the fact that its non-itch and allergy free and comes with flatlock stitching and this is a very comfortable base layer.
The zip isn't as generous as some but does still allow for additional temperature regulation, and I liked the high neck which adds to the warmth factor when zipped up, whilst the contrasting stitching cuts a bit of a dash.
Overall the Warm Flow is a clever mix of fabrics and makes for an effective and good looking base layer.