The Highwire is fast becoming a classic with its discrete peak styling. The tough wearing endura shell construction is well suited for those venturing into the park. Passive ventilation helps maintain airflow & the expedition fleece lined ear pads will keep you warm when needed. The Auto-Adjust fit system makes for a snug fit. Size guide: Small Medium Large 52-55cm 56-59cm 60-62cm Venting: Passive Sizing system: Auto-adjust Weight: 545g Construction: Hard Shell Safety standard: e N 1077 Class B, ASTM F2040 Venting Passive ventilation channels integrated into the helmet draw fresh air in the front & pulls moisture out the back. These built-in channels help to keep goggles clear & aid in maintaining a balanced & comfortable climate all day long. Anon’s goggle ventilation channel draws warm, moist air away from the top of your lens. Sizing system Auto-Adjust Fit System self-adjusts to the wearer’s head. It’s a lightweight, low complexity adjustment system that can expand or contract to provide a comfortable & secure fit. Constructionendura shell two-piece construction features an injection-moulded ABS exterior for long-lasting durability & ding-resistant strength. Built for season after season of knock-around wear & tear. Other features Anon has partnered with Fidlock, the award-winning designer of a new breed of ultra-fast & secure fasteners. Fidlock’s magnetic SNAP helmet buckle lets you open it with one h&, even if you’re wearing gloves—and closing it is just as easy, which means you can spend less time fiddling with your gear, & more time focusing on your riding.expedition fleece liner & ear pads are low pile & tough wearing, designed for maximum warmth & moisture-wicking during high heat riding & hiking. Compatible with Outdoor Tech aftermarket headphones.