The Navy Hidden Button Down Bamboo Stretch Long Sleeve Shirt is an American Heritage comfort fit. The shirt features performance stretch fabric for ease of movement, piped inner collar and side slit for extra style and comfort, as well as non-iron and moisture-wicking for easy care. Anti-microbial and SPF 50 technologies provide additional protection.77% Bamboo. 20% Rayon. 3% Spandex. American Heritage Navy Hidden Button Down Bamboo Stretch Long Sleeve Shirt