These Zascanauta tank tops are easy to use. Just put them on and enjoy the comfort. When it comes to washing, remember to use cold water and wash them inside out with clothes of similar colors. Only use non - chlorine bleach if needed. After washing, it's best to hang them dry. You can also use the cool or low - heat tumble - dry setting. Avoid using fabric softener because it can make the colors fade. And don't try to iron or dry - clean these tops, as it might damage the fabric. For sizes, men's and unisex tops range from XS to 2XL, while women's tops go from XS to 4XL. Choose the one that fits you best and have a great time wearing them!