Meet HeatGear Sonic. We started the performance revolution in sportswear with the original HeatGear. But since relentless innovation is part of our motto, we didn't stop there. This latest fabric takes comfort to the next level lighter, with a sleek, softer feel that you can wear all day. Ultra-soft, smooth fabric provides extreme comfort with very little weight. 4-way stretch fabrication allows greater mobility and maintains shape. Signature Moisture Transport System wicks sweat away from the body. Anti-odor technology prevents the growth of odor causing microbes. 30+ UPF protects your skin from the sun's harmful rays. Smooth, chafe-free flatlock seam construction.