Rear dial knob for head size adjustment. Side rails allow fitment of compatible accessories. Adhesive panels allow fitment for morale patches. Integrated helmet shroud allows fitment for NVG mounts. Interior helmet padding for comfort. Width and length adapter is fully adjustable. Adjustable head strap for most head sizes. Side rails provide bungie retention for NVG. In the Box 1X Helmet 2X 0.625 Goggle Clips 2X 1.25 Goggle Clips 1X NVG Mount Adapter 1X Side Rails w/ Bungie Retention for NVG Specifications: Helmet size L/XL Helmet fit 57CM-60CM Rail adapter 20MM X 1 California Proposition 65 Warning: Cancer and Reproductive Harm - www.P65Warnings.ca.gov