Enza Costa Silk Rib Sheath Tank in Black. Size M, S, XL, XS. 87% viscose 10% silk 3% lycra. Made in USA. Machine wash. Pull-on styling. Jersey knit fabric. Designed to transform everyday basics into luxury essentials, Enza Costa's unique brand of minimalist, modern clothing is crafted with featherweight blends of sumptuous supima cotton, cashmere and silk.