Introduing the all new Tour de France Special Edition Castelli Team Sky Aero Race 5.1 Jersey. After starting the aero jersey revolution in pro cycling, Castelli have continued to perfect this piece. While the 2015 Aero Race 5.0 Jersey represented the biggest leap forward in terms of race performance, the new 5.1 model builds on the race-leading aerodynamics while making the jersey more comfortable and durable. Updated fabrics on the front and back showed a 2 watt gain in the wind tunnel. But it’s not just aero; it’s also extremely light, coming in at just 103g. That’s about 40g lighter than a standard jersey and almost as light as Castelli's Climber’s Jersey.