The dual fabric fusion of the Arcteryx Sigma LT Jacket blocks the wind without overheating the core. WINDSTOPPER® fabric protects the front, while new Bonded Poly underarm panels channel excess heat away from the body. The Sigma LT features no-lift gusseted underarms and laminated construction for enhanced protection and freedom of movement. A Windstopper front warms in winter and a Bonded Poly back lets off enough steam to prevent in-the-track overheating.
During heart-pumping aerobic activities, the Sigma LT moderates rising internal and falling external temperatures.