Lululemon Swiftly Tech Long Sleeve Crew A long-sleeve layer designed with running (and sweating) in mind. Lightweight fabric and seamless construction keep you moving freely. Silverescent technology, powered by X-STATIC, inhibits the growth of odor-causing bacteria on the shirt. Mesh venting encourages airflow and keeps you cool. Thumbholes help keep your sleeves in place for easy layering. Tight fit, hip length. 58% Nylon, 34% Polyester, 4% X-STATIC Nylon.