STAY-COOL WICKING ULTRA-BREATHABLE FLATLOCK SEAMS FOR COMFORT REFLECTIVE DETAILS 4-ounce, 100% poly jersey with stay-cool wicking technology Self-fabric collar Reflective O heat transfer at back neck OGIO Endurance heat transfer label for tag-free comfort Set-in sleeves Reflective stacked O heat transfers at sleeves Reflective O Endurance heat transfer at back left hem