This is a high-performance base layer made with natural merino wool. BodyfitZone is the predecessor to the current ZoneKnit model, featuring a body-mapping construction that enhances breathability in different areas. It can be used for a wide range of activities, including mountain climbing, winter outdoor activities, and running. While there is no thickness designation, it feels like a midweight garment, equivalent to Merino 200. Material: 85% Wool 14% Nylon 1% Polyurethane This item was given to me by an acquaintance because the size didn't fit them. They only tried it on a few times and told me they never used it in the mountains. 【Condition】 ・Few pills, generally in good condition ・Minor fraying in some areas (please check the photos) ・For those who understand that this is a used item It has been home-cleaned, but please refrain from purchasing if you are sensitive to slight odors due to home storage. Thank you.