From the product website: Jersey knit and rib knit materials made by combining fine, slightly twisted yarns. Knitted at an extremely high gauge, it has no transparency, a beautiful surface texture, and an elegant luster. While having a substantial feel, it is also supple, and is a material that is useful in summer with its cool-to-the-touch and UV protection functions. Functions: Machine washable / Cool to the touch / UV care Size 1 (equivalent to M size) Black Length 55.0cm, Width 55.8cm, Sleeve length 48.0cm 7,990 yen I liked it and bought two each of white and black. I have similar items, and I don't have many opportunities to wear the second one, so I am selling it. Unopened and unused, but it has been stored at home, so please refrain from purchasing if you are sensitive to this.