How to measure for the right helmet size To determine the correct size, measure your head circumference. Use a flexible tape measure around the largest part of your head, about one inch above your eyebrows. If you prefer, wrap a string around your head and then measure its length with a ruler. Fit and adjustment Double adjustment system: a wellattached, longlasting dial for precise fit and an adjustable chin strap for comfortable wear. Removable lining Extra removable inner lining to accommodate different head sizes and make it easy to wash away sweat. Multisport design with ventilation Ventilation system provides airflow to help you stay cool during skating, cycling, BMX, MTB, and more. Use scenarios Daily city commuting on foot or bike: secure fit with quick size adjustments for allday comfort. Skatepark or BMX sessions: reliable protection during trick work with a snug, comfortable fit. Trail riding or mountain biking: breathable design helps keep you cool during longer rides. Key attributes Function: protects head with adjustable dial and secure chin strap. Compatibility: suitable for multiple sports including skating, cycling, BMX, and MTB. Size: adjustable via dial and removable liner to fit different head sizes. Material and performance: durable adjustment system, skinfriendly strap, and removable liner for easy cleaning.