The perfect base layer for moderate intensity endurance sports. Merino 3 is just warm enough for long climbing ascents in the backcountry. When you need a little more warmth, the hood is perfect to take the chill off without stopping to get something from your pack. Another feature I love is that there are no bothersome tags to irritate the back of your neck. No matter how careful I am, sometimes I accidently cut a whole while trying to remove tags from new cloths. I think they should ban tags at the back of the neck.