★ NOT suitable for big head!!!!! Internal width: 6.69" (17cm); Internal length: 8.46" (21.5cm).Fits for head circumference about 59cm (23 inch)or below,//***Warning: This item is for adult only ★ 100% brand new High quality ABS material,Weight:550g.Adjustable suspender straps and chin/neck pad for fitting, you can find the suitable size ★The NVG mount ahead was designed to fix corresponding/optical equipment,actical rails locate on both sides can fix most of the accessories like night-vision device/flash-light/communications headsets etc ★ airsoft goggles probably can handle up to about 550 Fps,you no need to wear other glasses,also the goggles part can go back into that helmet ★Perfect For Training, Search and Rescue, Climbing, Riding, Jumping, CS Airsoft and Paintball Games,security guard duty and other outdoor activities. ★Perfect For Training, Search and Rescue, Climbing, Riding, Jumping, CS Airsoft and Paintball Games,security guard duty and other outdoor activities. Great protection for airsoft/ paintball