XS-XL - Alo ladies' bamboo racerback tank. 67% bamboo lyocell, 29% cotton, 4% spandex jersey. Racerback. Contrast thread at bottom hem. Bamboo has natural inherent properties that wick moisture and is naturally anti-bacterial, hypoallergenic and breathable with no added chemical treatments. StretchFlex (TM) technology provides garment with comfort, freedom of movement, lasting recovery and a great fit.