This is a karrimor Thermal Crew, women's XS size. Worn once in Autumn 2025. I bought it because I liked how light and warm it was, but it was overkill for me. Although labeled XS, it corresponds to a Japanese S-M size. The following is quoted from the official website: Thermal Crew A lightweight mid-layer that is active year-round. Uses Octa®, a hollow fiber with 8 protrusions, which is half the weight of regular polyester fibers. Highly elastic and traps dead air, providing excellent warmth, quick-drying properties, and antibacterial and deodorizing treatment. Versatile as activewear for various situations. Polygiene StayFresh™ throughout. *I keep pets indoors. Please be aware if you have allergies. - Brand: karrimor - Size: XS - Color: Black - Material: Mesh