Sugoi Women's Jackie Singlet Body 100% Polyester / Mesh Under Upper Back 75% Polyester, 25% Spandex Imported Flat seams for increased comfort Moisture wicking, antimicrobial fabric for breathability and cooling and UPF 50+ protection Back yoke mesh vents provide increased moisture management Contoured hemline gives a smooth drape on the body and prevents rising while running Flat seams for increased comfort