Shell Material: polycarbonate Ventilation: 15 Wind Tunnel vents, internal channeling Fit Adjustment: Roc Loc 5 Air Certifications: Complies with U.S. CPSC Safety Standard for Bicycle Helmets for Persons Age 5 and Older, CE EN1078 Claimed Weight: [medium] 9.5oz (270g) Slotting in just above the updated Synthe MIPS II, the all-new Giro Helios Spherical Helmet serves as Giro’s premium adventure helmet. With Giro calling out the Helio’s primary safety feature in its appellation, it’s clear that the focus of cycling helmet evolution continues to be rider comfort and protection. For those unfamiliar, spherical technology is a brain-child of Bell + Giro Dome in partnership with MIPS. The unique ball-and-socket design, thankfully, is easy to conceptualize. The Helios Spherical is a Progressive Layering system with an inner and an outer liner that can rotate around each other in an impact. All you have to do to visualize this is make a fist, and then rotate your other hand over the fist. The result is a more comprehensive platform for rider protection. Giro doesn’t stop there, however, as the Helios Spherical is aimed straight at the adventure cyclist with 15 Wind Tunnel vents and channels that run deeply in the underside of the helmet to keep heads cool during epic, route-free riding.