Regular fit COS T-shirt in white size small. I bought it wear it once and it’s just sitting in my closet. Details linked here. https://www.cos.com/en_usd/women/womenswear/t-shirts/product.regular-fit-t-shirt-white.0753391001.html An understated essential, this white T-shirt is made from cotton with a soft jersey quality. Cut for a straight, regular fit, it has a round neck with tightly ribbed detail and it is finished with neat topstitching at the edges. - Short sleeves 100% Cotton / Machine washable Back length of size S is 25.19" / Model is 5'9" tall and wears a size S