What's it do? The original UA training t-shirt was called Performance Grey and it was built from a lightweight, natural-feeling synthetic that can wick sweat and dry fast. That meant athletes could stay cooler and drier. Since that time, we've updated the name to UA Tech™, made it even softer and more comfortable, and blown it out with colors. It's the shirt that started the legacy and there's a reason you still see it everywhere. THE FUNDAMENTALS Lightweight UA Tech™ fabric with an ultra-soft, natural feel for unrivaled comfort Signature Moisture Transport System wicks sweat away from the body Anti-Odor technology prevents the growth of odor-causing microbes Smooth, chafe-free flatlock seam construction Polyester Imported.