This three layer, waterproof and breathable shell material is the foundation for much of Columbia's technical apparel. The outermost shell layer consists of a stain and water resistant Omni-Shield® coating that helps fight dirt and grime buildup. The majority of the waterproofing comes from a membrane within the second layer. The third layer aids in the transfer of heat and moisture outwards through the other layers. The lack of total waterproofing in the outermost layer is a quality that allows for dirt and grim to be easily removed during washing, without affecting the waterproof coating in the second layer.