Giro Advantage 2 TT Helmet This is the time trial helmet of choice for great champions like Lance Armstrong, Alberto Contador, Levi Leipheimer, Dave Zabriskie, and David Millar. Wind tunnel testing proves why it is so popularóAdvantage 2 represents the pinnacle of aerodynamic performance, fit, and ventilation. Advantage 2 is the ultimate helmet to wear when every thousandth of a second counts, from prestigious prologues at le Tour to ultra distance triathlons. TechnologyIn-mold construction fuses a tough polycarbonate outer shell with the helmetís impact-absorbing foam liner. The fusion process allows us to sculpt better ventilation systems, so In-mold helmets can be lighter and cooler than traditional helmets. Wind Tunnel VentilationGiro helmets are developed utilizing our proprietary Wind Tunnelô ventilation system, which combines active vents with internal exhaust channels that thrust cool, fresh air over and around the riders head-while forcing heat and stale air out. This significant increase in air channeling makes a difference that riders will immediately feel and appreciate. Roc Loc 5 After more than two-years of development, Giro introduces Roc Loc 5. This groundbreaking fit system provides an entirely unique user experience with an unmatched level of comfort, stability, adjustability and weight savings. With Roc Loc 5, you can easily dial-in both fit tension and adjust vertical position with a single hand. Just twist the dial for a tighter feel on rough terrain, then back it off a notch and relax across the flats or a warm climb. Even with these remarkable features, Roc Loc 5 is still nearly 40-percent lighter than its popular predecessor, Roc Loc 4. Micro Dial: The heart of Roc Loc 5 is this ratcheting, micro-adjusting dial. A simple, two-finger twist of the Micro Dial opens or closes the retention system and each click is audible. Three-Position Bracket: Itís never been easier to change vertical positions and fine-tune fit. We incorporated a three-position bracket that features 15-millimeters of up/down movement. Like the Micro Dial, this system can be adjusted without removing the helmet. Carefully-crafted ergonomic arms are shaped to be as comfortable as possible, yet work flawlessly with Giro eyewear (what we call Super Fit engineering). Dual Pods: These two panels are designed to firmly grasp the back of your head while comfortably cradling the occipital lobe. Strap Baskets: With Roc Loc 5, your helmet straps are always right where you need them. Not to mention this strap basket brings a new level of comfort.