Worn as an outer layer during cold-weather aerobic activities or as a layering piece when an expedition-weight base layers is required, the Arcteryx Rho AR Bottom for Boys will keep you warm and dry; built with insulating Polartec Power Stretch Fleece that also works to wick moisture away from your skin. Durable on the outside, with next-to-skin softness on the inside, the Rho AR Bottoms are an Must have addition to your active, cold-weather Closet.