Lululemon Base Runner Long Sleeve Size: 2 ( Please refer to Lululemon's Size Chart Provided in Photos) Color: Straightup Stripe Black White / Black We designed this slim-fitting top to keep us warm when we're out in the winter air. Made of sweat-wicking Rulu, it feels oh-so-soft when we wear it against our skin, and fits easily over a tank or under a jacket. Layer up, let's go! soft, four-way stretch Rulu fabric is sweat wicking and breathable, ribbed Power Luxtreme fabric on the sides helps keep this shirt in place, lightweight Mesh panels under the arms give you room to blow off steam, thumbholes help keep your sleeves down and your hands warm, reflective details help keep you visible in low-light situations, chafe-resistant flat seams help keep you comfortable s/h: 24 inches , a/a: 15 inches