Plasma work helmets were designed for professional applications. They are lightweight, tough, and uber-comfortable. Every helmet contains ten aluminum-grilled air vents that provide efficient cooling and ventilation while blocking out debris. The rubberized wheel for headband size adjustment is easy to use even while wearing gloves. The high-density ABS plastic outer shell is designed to withstand significant impact from above or from the side, and meets CE EN 397 and CE EN 12492 standards. The high-density polystyrene inner shell has ducts, allowing for natural air flow and heat cycling. Inner padding consists of two pieces�a soft polyethelene headband and disc, both of which are removable and washable. The liner is made of anti-allergic, moisture-absorbent, odor-resistant fabric. Size: Universal-adjustable from 53 to 63cm