A performance top for cooler conditions delivered in a temperature-regulating Merino blend. One of Tracksmith's original products, refined over the years, perfecting the design utilizing the soft and durable material to create a layer that moves with you, matching the rigor of your runs year after year after year. A constant in Tracksmith’s wardrobe, the Harrier has endured the test of time for a reason: what works, just works. 89% Merino Wool / 11% Nylon, 170 gsm Wore this twice- just was a little small for me, but true to size! It’s amazing how this shirt doesn’t smell after sweating in it- the Merino works wonders.