Zoot Sports Men's Ultra Recovery 2.0 CRX Long Sleeve Top 70% polyester/30% spandex with SilverTECH Imported . ZoneRx = increased oxygen delivery to muscles Places direct pressure on the muscles to prevent post-exercise swelling by forcing lactic acid out of the muscles, thus speeding post-workout recovery NEW - Lighter-weight advanced polyester transports moisture away from the body to the garment's surface, spreading quickly and drying faster . CRx = improved blood circulation 18-30mmHg compression level