The players called them "sweatshirts", "undershirts" or just "sleeves". They were handed out in the locker room as part of the uniform. Years ago we found an original baseball undershirt from the 1950s still in its wrapper and we tracked down the mill that made them for all the uniform manufacturers. After a few years when we could not get them, the original two-layer "fungo" shirt is back! This shirt is made of a merino wool blend outer layer. The aerated cotton inner layer is designed to absorb sweat. Two-button henley placket. The navy contrast sleeves complete its authenticity. Wear under your EFF flannel, or by itself for a great workout or casual shirt. Made in Canada.