HEATTECH ULTRA WARM black long-sleeved cut-and-sew, XL size, excellent heat retention. I wore an undershirt underneath, so I think it's hygienic. - Brand: HEATTECH - Model Name: ULTRA WARM - Size: XL - Color: Black - Material: Polyester - Manufacturing Year: I believe it's the 2022-23 model (※Corrected manufacturing year: 2021 winter model) Thank you for viewing. Size: XL (LL) "Additional Product Details" Uniqlo HEATTECH Ultra Warm High Neck T-shirt, Extra Warm 2021 The 2021 Uniqlo Extra Warm (Extra Warm) high-neck T-shirt features a 100% cotton inner lining for a comfortable feel, a material with a firm texture that doesn't cling to the body, and the same functions such as "heat retention, heat generation, moisture absorption/release, and antibacterial/odor control," while being warmer than regular HEATTECH. In particular, it is thin yet warm, and designed to be less bulky when layered, making it suitable for sudden cold spells and situations where you frequently go between indoors and outdoors. Main features of the 2021 model Feel and Material: The brushed surface on the skin side is 100% cotton, gentle and comfortable on the skin. The material has a firm texture that doesn't cling to the body lines, making it easy to wear even as a single layer. Functionality: Equipped with moisture-absorbing heat generation and heat retention functions, it is warmer than regular HEATTECH. Excellent stretch and shape retention, making it resistant to deformation even after washing. Also equipped with antibacterial, odor-resistant, and moisture-absorbing/releasing functions. Wearing Comfort: The point is that it is thin and light compared to the "Extra Warm" image, yet still warm. Optimal for areas with severe cold or for those who are active outdoors. It's one model before the next year's Extra Warm model, but it's 100% cotton, so in my personal opinion, it might be good for those with sensitive skin.