Arc'teryx Women's Phase AR Bottom SmallA women's midweight baselayer for high output in cooler temperatures, the Phase AR Bottom is made from next generation Phasic AR. An Arc'teryx fabric engineered to provide insulation, dry quickly, and offer performance stretch, Phasic AR uses different polyester yarn structures on its interior and face to most effectively wick and disperse moisture. Lighter weight Phasic SL panels at the back of the knees improve thermal regulation and reduce bulk.