Alpinestars SM3 Radium Helmet — Size L

Engineered for MX, enduro and off-road riding, the SM3 Radium helmet balances comfort, usability and impact performance.

• Thermo-injected shell with a graded polymer blend for high impact protection and low weight.
• Patented low-friction coating on the main EPS liner reduces rotational acceleration in oblique impacts.
• A dedicated slip-plane layer mimics cerebrospinal fluid to limit rotational forces on the brain.
• Patented visor release system reduces neck loads by releasing at a predetermined force.
• Maximized ventilation with 10 inlets and 7 exhaust ports for efficient heat exchange.