The Lululemon Run Full Tilt Half Zip is a slim-fitting, warm running top made from soft, sweat-wicking Rulu fabric with four-way stretch, designed to keep you warm and dry in cool weather with features like thumbholes, reflective details, a hidden pocket for keys/gels, and breathable mesh panels for ventilation. It's built for running, offering warmth without bulk, and uses chafe-resistant seams for comfort during movement.