Tracksmith launched our Harrier tops in 2014 and they quickly became a must-have for runners. The natural properties of the Merino make them odor-resistant, run after run, without washing. But they knew there was even more we could achieve, setting off a years-long search for natural performance gold. Introducing the new supercharged Harrier Tee with 37.5® Technology - an innovative treatment that keeps you cool by discarding moisture while it's still in vapour form. If it sounds a bit like magic, it is.