Given the discipline's solitary nature, the jet engine triathlete's only real enemies on the bike leg are bonking and wind drag. Castelli designed the men's T1:Stealth Jersey to address them both, particularly the latter. By combining Velocity front panels and Velocity Mesh shoulder and back panels, Castelli imbues the T1:Stealth with hydrophobic, quick drying properties and a stealthy, flat lying fit that eliminates wind catching, transitional ridges from panel to panel and jersey to skin. The result is a claimed three minute gain on Castelli's two time Kona champion Free Tri Suit over century distances. To ward off bonking, Castelli includes two pockets on the lower back. The pockets provide enough space for gels, energy gummies, and power waffles, and the side oriented openings effectively reduce their aerodynamic profile in order to preserve the gains made by the jersey's fit. The elastic, silicone gripping waist helps keep that fit in place, and the addition of UPF 16 sun protection helps your sunscreen keep up during hours long events.