Spyder's zip t-necks have become a perennial best-seller for the winter, but warmer sunnier months demand different performance without sacrificing style. Say goodbye to hot spots and avoid overheating in the Arc Graphene Tech Zip. Made with Spyder's EXO THERMO graphene technology, which spreads body temperature throughout the garment. The Arc is UPF 50+, and made with 89% polyester to keep you protected from the sun, and is fast-drying.