Hot Chillys Women's F8 Perform 8K Crewneck Tee 89% Polyester, 11% Spandex Made in the USA or Imported Articulated construction and Four-Way stretch MTF (moisture transfer fiber) wicks energy-sapping perspiration UV protection of UPF 40 Midweight, Moisture-Wicking Fabric (Moisture Transfer Fibers) Ultraviolet Protection Factor 30+ Bio-Silver Anti-Microbial Odor Blocking Properties The Chamois fabric has a lightly brushed interior for a soft, fleecy next-to-skin feel