Built-in high-definition headset: Built-in high-definition sound quality tactical headset in the all-in-one helmet, no need for additional Wear headphones for added convenience. suitable head circunference is 54-64cm/21.2 -25.2 . Flip mask: Press the front button and the mask part pops up automatically. Built-in anti-fog fan: Controlled by the buttons on the back to prevent the goggles from fogging. Upgrade NVG bracket: Lightweight NVG bracket, composed of removable inserts, new NVG anti-drop bungee cord. Back battery compartment: The battery compartment is designed on the back of the helmet, powered by 3 AA batteries (not included), which is convenient for users to supply. Size Medium Color Black Brand Name CZMYCBG Model Name CZMYCBG Unit Count 1.0 Count Item Weight 3.75 Pounds Manufacturer CZMYCBG Inner Material Nylon Outer Material Acrylonitrile Butadiene Styrene (ABS) Additional Features Adjustable,Lightweight Age Range Description Adult Manufacturer Part Number 1392874989--64710886 Recommended Uses For Product outdoor