Giro: ADVANCED PERFORNANCE FOR SPEED AND ADVENTURE The heart of the Helios’ extraordinary design and performance is Spherical Technology, which utilizes a ball-and-socket design powered by MIPS®, the market-leading brain protection system that can help to reduce rotational forces.Spherical Technology allows the helmet’s outer liner to rotate around the inner liner during a crash, and also allows Progressive Layering of the inner and outer liners to provide more comprehensive protection and performance.In addition to advanced head protection, the Helios’ 15 Wind Tunnel vents provide exceptional cooling power that’s enhanced by our patented Roc Loc 5 Air fit system and plush, antimicrobial Ionic+ padding for exceptional sweat absorption.It’s the ideal match for your road and gravel adventures. SPECS- Spherical Technology™- Mips® brain protection system- Progressive Layering- Nanobead EPS- Ionic+™ anti-microbial padding- Reflective decalsCONSTRUCTION- Independent, In-Mold liners with spherical ball-and-socket design- In-Mold polycarbonate shell with EPS liner- Full lower Hardbody coverageFIT SYSTEM- Roc Loc® 5 Air- VENTILATION- 15 Wind Tunnel™ vents and deep internal channelingSUPER FIT™ SIZES- S 20”–21.75” / 51–55cm- M 21.75”–23.25” / 55–59cm- L 23.25”–24.75” / 59–63cm