We launched our Harrier tops in 2014 and they quickly became a year-round staple for runners. Even so, after a decade of wear, we decided it was time for an upgrade. Touting the classic comfort of your everyday, basic tee but with top-notch materials and state-of-the-art technology, the natural properties of the Merino alone make them odor-resistant, run after run, without washing. We supercharged the Harrier Tee with 37.5® Technology - an innovative treatment that keeps you cool by discarding heat while it's still in vapor form. If it sounds a bit like magic, it is. We've struck natural performance gold.