GRAY Triathlon/Time Trial TT Aero Helmet - Black Weighs 345 grams, One size fits all 4-Vent internal channeling, CPSC approved, Chin strap protector Drag: 3.306, Drag @ 25 mph : 3.260, Drag Coefficient: 0.2465 Flexible side panels, DuraShell in-mold construction Lifetime crash replacement warranty