OneTigris Multifunctional Tactical Airsoft Helmet Comes with goggles, not only for tactical activities but also can be used for cycling One-piece base for connecting headlights, camera, night-vision and so on, reduction of extra cost to purchase a night vision mounting base Loop panels along the sides and back for attaching personality chapter Adjustable headband, knobs for adjusting the tightness of helmet; telephone headset can be placed inside the helmet, reducing trouble for the extra process of wearing headset Internal size: 6.69 x 8.66 inch, fits for head circumference 21.623.6inch/5560cm