These are 100% polyester t-shirts with cotton feel. They are not see through or thin shirts like some poly shirts can be.
Unisex sizing to US sizes and are true to size. Very close in size to a Gildan SoftStyle, though they do not have as much stretch, for comparison.
Available in sizes are Small to 2XL
Size chart measurements - Chest (C), Length (L) & Sleeve Length (S)
Small - C 19" - L 25" - S 7"
Medium - C 20" - L 26" - S 7.5"
Large - C 22" - L 28" - S 8.5"
X-Large - C 23" - L 28.5" - S 9"
2X-Large - C 24" - L 30" - S 9.5"
(+/- .75)