Incredibly versatile, the long sleeve Comfort-T from On is a real 3-in-1 active top. We use ours as a mid-weight primary top for crisp fall and early spring runs, a baselayer for the colder months, and a refined yet comfy tee when we're off-duty. This versatility is due in part to a polyester-wool blend in a special fiber construction that offers the breathable comfort and anti-odor properties of wool without the itch. Combined with a flattering, relaxed fit and engineered anotomical seems, the Comfort-T is the ultimate blend of utility and style.