The lightweight Nike Dri-FIT® Element Half-Zip Running Top is the perfect base layer with its soft, sueded Dri-FIT® fabric. Gussets at the underarms provide ventilation and maintain optimal temperature. Works great for both layering in colder weather or by itself on warm days. 360º reflectivity optimizes visibility in low light. Thumbholes are available to keep the sleeves in place on cold-weather runs.