Similar in construction to our extremely popular Loose Fit Undergear, the FLASH™ Short Sleeve shirt adds fire resistance. Dri-X-treme™ anti-microbial, moisture wicking technology and standard Undergear™ construction like saddle shoulders, and flat-lock seams. 4 ounce 51% S.P™ Cotton /49% FR-x3™ modacrylic fire-resistant jersey fabric.