It's just like its name says

loopwheeled cotton fabric

and when zipped it has a double layer of leather on the front panels to increase wind resistance

The collar as been attached with The Flat Head's distinct triple needle stitch

Knickerbocker Rib Pocket T-shirt - Black personalcare It's just like its nameThe Rib Pocket T Shirt is built from a custom jersey made with long staple, dual ring spun, combed cotton, giving it a soft feel with solid durability behind it. The drop needle construction adds a subtle ribbed texture that sets it apart in a tastefully subtle way. Its finished with a mounted collar, a nod to classic sportswear.