SIANKO-PJ FAST Tactical Helmet Set 1. To turn on the noise reduction function of the headset, you need to install AAA batteries*2 (not included). 2. The headset communication function requires connection to PTT (not included). 3. The earphones have a detachable microphone that can be freely adjusted left and right. 4. The flashlight has three levels of adjustment: constant light, low light, and strobe. 5. The size of the helmet can be adjusted freely. Packaging details: Helmet*1, hood*1, flashlight*1, clip*1, goggles*1, earphones*1, signal light*1, battery pack*1, L4G24 metal bracket, four-eye telescope model*1 (If you need more high-quality tactical/outdoor equipment, please search "SIANKO")