High performance activity requires high-performance clothing. The Women's Mountain Hardwear Effusion Power Jacket combines Active Solution(TM) 3L Jersey panels on the front, to give you maximum wind and water protection, with single-knit jersey material on the back and under the arms for superior moisture-wicking, breathability and stretch . Designed for the runner who wants a streamlined running jacket with weather protection where it matters most. Thumb loop has a half-glove cuff that folds over to keep your hands warm on colder days.