Ideal for wear in mild conditions, the relaxed crew neck and lightweight, 4-way stretch polyester and spandex-knit construction of the TRX LW Performance Short-Sleeve Crew result in a comfortably cool and perfectly flexible shirt. When things do heat up, wearers can count on the shirt's UPF 50+ rating and integrated antimicrobial treatment to block harmful UV rays and fight odor-causing bacteria, keeping gear fresher, longer. Size X-Large