Columbia Boys Silver Ridge Short Sleeve Tee 100% Other Fibers Imported Omni-Wick jersey 87% polyester / 13% elastane Omni-Shade UPF 50 sun protection Antimicrobial treatment protects this product from bacterial growth Omni-Wick Advanced Evaporation Omni-Shade UPF 50 sun protection Intended to protect the garment from odor Caused by bacteria