Recycled Nylon - ionic+™ technology with naturally occurring antimicrobial silver ions knit in the fabric eliminates odor before it starts. BREATHABLE: Airflow moves easily through the garment. RATED UPF 50+ (Excellent Protection). FOR: Tennis, running, or golf. FEEL: Seamless construction for maximum comfort and minimal chafing. Machine wash and dry. Fitted next to the body. Shirt is not longer perfectly white as it has been washed, but no yellowing stains or damage. Athleta no longer makes these polos (though their Momentum collection is still some of their bestsellers!). By far the most flattering athletic polos I have found! I just don't golf anymore. Comes from a non-smoking and pet-free home.