Hot Chillys Men's Chamois Zip-T Base Layer Top 89% polyester/11% spandex Made in the USA and Imported A blend of 90% MTF micro polyester, Bio-Silver polyester and 10% spandex, which is lightly sanded for comfort and performance. A blend of 90% MTF micro polyester, Bio-Silver polyester and 10% spandex, which is lightly sanded for comfort and performance.|Zip-through collar construction for ultimate warmth|Flat seam construction to reduce bulk & abrasion|Made is USA, China & Vietnam|