The Under Armour B HEATGEAR SS boys' t-shirt is made of ultra-light, soft and smooth HeatGear material for maximum comfort. Strategic mesh panels ensure better ventilation where it is needed most. The construction with 4-Way Stretch allows for flexibility in every direction. The material wicks sweat and dries quickly, so you stay fresh even after a demanding sports performance. Ergonomic flat seams increase comfort and movement.