Giro Nine Snow Helmet - Men's IN FORM FIT SYSTEM - The In Form Fit System makes it easy to dial in a custom fit in secondseven with gloves on. An ergo-friendly dial at the base of the helmet provides up to 6cm of adjustment and enhanced stability. The Vertical Tuning feature accommodates different goggles and head shapes for a custom fit free of gaper gap. THERMOSTAT CONTROL ADJUSTABLE VENTING - Adjustable venting allows you to control the air vents. Close them on a cold, snowy day. Open them up on a warm spring day. The adjustable vent allows you to remain comfortable with just the slide of your finger. IN-MOLD CONSTRUCTION - In-Mold Construction fuses a tough polycarbonate outer shell with the helmets impact-absorbing foam liner. The fusion process allows for better ventilation systems, making In-Mold helmets lighter and cooler than traditional helmets. STACK VENT Our Stack Vent was developed based on research showing the majority of the warm air that can cause fogging exhausts from the center top vent of the goggle. Aligning the Stack Vent in the helmet with the vent of your goggles helps to keep them clear and fog free. AUDIO READY - The earpads in the Giro Nine have slots ready to drop in your aftermarket audio. Drop in 40mm speakers from any brand. Comes in 4 Sizes - Small (51-55cm), Medium (55-59cm), Large (59-63cm), and XL (63-67cm)