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Product Specifications


95% Polyester/5% Elastane

Item #


Style #


US sales only.

Item is returnable, but does not qualify for free returns.

Under Armour Reactor Run Short Sleeve Tee Men's

Taking over as the next big technical running top, the Under Armour Reactor Run Short Sleeve Tee for men features well-crafted technology. The ColdGear® Reactor technology offers Smart Insulation that provides adaptive, balanced warmth during any level of activity. This lightweight, fitted style is made from 4-way stretch fabric for ultimate freedom of movement.

  • Reflective UA logo at left sleeve and at back yoke.
  • Features 360° Reflectivity for enhanced visibility.
  • ColdGear® Reactor helps regulate warmth to keep the body temperature balanced.
  • Fitted style helps provide an athletic look and feel.
  • Specialized panels at high-heat zones offer enhanced comfort.


Small: 35-37" chest
Medium: 38-40" chest
Large: 41-43" chest
Extra Large: 44-46" chest
2XL: 47-49" chest

*Measurements refer to body size, not garment size.