There are two choices for the long sleeve T-shirts: 1) made of 50% cotton/50% polyester 2) Moisture wicking (Dri Fit style) made of 100% polyester. The cotton blends are available from size youth small up to adult 6X. (5400B/PC54YLS/29LS/PC55LS): The moisture wicking shirts are available from youth small XS up to adult 4X (YST350LS/ST350LS)