Under Armour Womens Fit Guide All Under Armour(R) Apparel features a tagless design or tear-away tag with no left-over pieces. Move all around on the ground while practising your favorite sports by wearing Under Armour(R) Train Seamless Tank. It features a crew neck, pull-on style, and soft knit fabric with engineered mesh ventilation, mapped to the places you need it most. Nearly sew-free design eliminates chafing while classic racerback sleeveless design of the tank offers full range of motion. 100% polyester. Machine washable.