When you are on your bike, the two of you meld into an aerodynamic machine that's designed to devour miles and cut through the air. The CamelBak Women's Racebak Hydration Jersey is a thermo-regulating base layer that features an integrated 70-ounce water bladder so that your speed machine stays hydrated and you can keep going without fiddling with bottles.Breathable, Quickwick fabric increases sweat evaporation to keep you cool on hot daysQuickFit mesh hugs your body and holds your hydration reservoir close so it won't move around on youInsulated hydration pad prevents your body heat from simmering your water, or you can take it out and let that icy water keep your core coolHelmet-friendly design means you won't have to pull your helmet off to refill