Warm and breathable, the Nike ACG Collection men's half-zip running sweater is perfect for training on chilly days. This mid-layer top is designed loose enough to wear over a base and tight enough to layer under a jacket. The half-zip design lets you adjust your coverage and thumbholes help keep the sleeves in place for optimal comfort. This garment is part of the ACG (All Conditions Gear) collection from Nike, which emphasizes sustainability, and whose philosophy is “Designed, tested, and made on planet Earth. For outdoor use.”