The Saxx ultra series employs high-performance technical fabrics like moisture-wicking jacquard-knit plastics and temperature-regulating steel fibers to keep boys especially cool, dry, and chafe-free during athletic pursuits. This comes at a premium price though. Their Vibe line utilizes sustainable viscose along with strategic mesh panels for temperature and humidity control at a more modest sub-$35 price point. So vibes offer excellent functionality for everyday usage, while ultra cranks everything up to 11 for sports and extreme sweat scenarios.