Lancer Tactical Large - X-Large Industrial ABS Plastic Constructed Maritime Helmet Adjustable Crown 20mm Side Rail Adapter Velcro Padding NVG Shroud Bungee Retention Adjustment Rear Dial Knob for Head Size adjustment. Side Rails w/ Goggle Strap Clips & NVG Shroud Velcro Panels Allow Fitment of Patches Lightweight But Durable High Quality Construction for Head Protection