As low as $69.99/mo with or . (Pay in 4 interest-free payments)
ALPINESTARS SM3 Radium Helmet (Matte Gray/Black/Yellow Fluo) Built for MX, Enduro, and off-road riding, the ALPINESTARS SM3 Radium helmet delivers an optimized mix of impact protection , lightweight performance , and all-day comfort. The matte gray/black/yellow fluo Radium graphic stands out while advanced construction helps manage both direct and oblique impacts. Key Protection & Construction Thermo-injected shell with polymer blend and varied thickness for the best balance of protection and weight Lightweight thermoplastic outer shell for durable impact resistance Composite fiber inner shell positioned between outer shell and EPS liner for maximum protection 6-piece EPS liner with five densities to improve impact absorption and control volume Rotational impact management using polished EPS with a special low-friction coating Engineered for oblique impacts with inner/outer surface design to reduce effects Comfort, Fit & Ventilation 10 inlets & 7 exhaust ports for maximized airflow and heat transfer Visor airflow design directs air to the ports Adjustable fit with crown and cheek pad tailoring Hydration tube channels integrated in the cheek pads 25 mm soft textile chin strap for safety and comfort Safety Features Emergency Release System with removable cheek pads 3D contoured foam for secure, comfortable wear Stainless steel D-rings for a tight and secure fit Riding Style: Off-Road / MX / UTV / ATV | Gender: Unisex | Weight: 5.1 lbs | Size: Medium | Dimensions: 16.25" x 13" x 11"
Varied thickness shell construction for optimized protection and light weight
Optimized for MX, Enduro, and Offroad use
Delivers blend of performance, protection, and comfort
Key Features
Features thermo-injected shell incorporating a polymer blend enhanced by varying degrees of thickness that is engineered to deliver the optimal combination of impact protection and light weight
Lightweight outer shell is constructed from impact resistant thermoplastic
Inner shell constructed with a composite fiber assembled between the outer shell and the EPS liner for maximum protection against impacts
Fit can be tailored to the rider's head thanks to the helmet's crown and cheek pads
Construction
Multiple density inner liner ensures the helmet is equipped with the correct density in the correct area for enhanced impact absorption, while also helping to reduce overall weight
6-piece EPS liner with five densities to effectively manage volume and impact performance
Polished inner EPS liner with special coating to reduce friction with comfort liner for rotational impact management
The inner and outer surfaces are engineered to minimize the effects of oblique impacts
Low friction coating is applied to the inner part of the main EPS liner to reduce the rotational acceleration forces that can result form certain oblique impacts
Maximized ventilation and high levels of heat transfer exchange thanks to ten inlets and seven exhaust ports
The visor has been designed to direct air into the ports for enhanced airflow
Visor release system ensures the visor is released with the correct pre-determined amount of force, effectively reducing the forces on the rider's neck during an impact
Comfort liner is constructed using recycled materials for a lower carbon footprint
Hydration tube channels are integrated into the helmet's cheek pads for convenience and performance
Soft textile chin strap is 25 mm for optimal safety and rider comfort
Protection
Equipped with an Emergency Release System and removable cheek pads to permit the safe and easy removal of the cheek pads while the helmet is still on, while the 3D contoured foam ensures rider comfort
Chin area optimized for superior impact performance
Stainless steel D-rings ensure a tight and secure fit
or 
. (Pay in 4 interest-free payments)
